Here's a selection of terms that you may have heard before when referencing Internet Marketing or Search Engine Optimization. 

'above the fold'
Adapted from the reference to headlines on printed newspapers, 'above the fold' refers to the part of a webpage that can be viewed by a user without needing to scroll their window.

About
www.about.com Originally known as 'The Mining Company', today, About is one of the largest search engines on the Internet containing resources and expert articles on thousands of topics.

Acquisition
The point at which a website visitor becomes a customer or qualified lead; i.e. buying a product or subscribing to a newsletter.

Ad Broker
In web marketing this is often used as a term for an advertising specialist. Ad Brokers, as any brokers, act as the pass-through between advertisers and advertising venues.

Ad Inventory
The total number of potential web page views that a website has for advertisers.

Adjacency
The relationship or distance between words used in a user’s search engine query. Search engines typically assign higher value to pages where the search terms appear next to one another than to pages where the search terms are dispersed around the page or source code.

AdSense
Google's contextual advertising program for publishers. Seen on thousands of websites across thousands of topics, these advertisements are drawn from the Google AdWords "sponsored listings" program.

Advanced Search
An option offered by many search engines that allows users to utilize more specific search criteria. For example, users can elect to see only documents added to the database after a certain date, documents in specific languages, documents of a specific file type, etc.

AdWords
Google's pay-per-click advertising program. Individual keyphrases are bid upon by as many advertisers interested in the phrase. These results are displayed in the SERPs as well as in the 'content network' through the Google AdSense program.

Affiliate (Programs, Links, Websites)
Affiliate programs allow webmasters to sell products on a commission basis for various merchants on the Internet. Affiliate programs also allow merchants to have an evergrowing sales force to distribute and promote their products on the web. Affiliates work as a pass-through, using custom-tagged links to identify themselves as an affiliate. When a merchant receives a lead or sale through an affiliates custom link, that affiliate is paid a pre-specified amount in a commission.

Agent Name Delivery
Also knows as cloaking, agent name delivery is the process of displaying different webpages for the same URL, depending on who the viewer is. Each search engine has an 'agent name' and you can present different page versions based on which agent name is visiting the URL.

Algorithm
Algorithms are sets of rules according to which search engines rank web pages. Figuring out the algorithms is a major part of SEO. The thinking is that if you understand how they calculate relevance, you can make specific pages on your site super relevant for specific search terms.

Algorithmic Search
A term often used to distinguish between algorithm based search engines like Google and payment driven search engines like Overture. All search engines, however, have some form of an algorithm working behind the scenes.

allintitle
An advanced search command on Google that will only return results that contain your search phrase in the page title.

allinurl
An advanced search command on Google that will only return results that contain your search phrase in the page URL.

AllTheWeb
www.alltheweb.com
Large search engine recently purchased by Overture and still one of the 2nd tier engines. Today, AllTheWeb's organic results are powered by the Yahoo search engine.

Alt Tag (alt attribute)
In HTML, the alt tag is an attribute assigned to an image. The contents of the tag are displayed when the image is 'moused-over' by a viewer. In many browsers, the alt tag will be displayed in the event that the image was unable to be downloaded. Alt tags used to hold strong influence on search engine rankings, however, today they hold little importance in that respect.

Alt Text
The content specified in the HTML image alt tag.

AltaVista
www.altavista.com
A pioneer in search engine technology and ethics, they were purchased by Overture in February of 2003. Today, AltaVista has organic search results provided by Yahoo, directory results provided by DMOZ, and paid results provided by Overture.

Anchor Text
Also referred to as link text, this refers to the visible, hyperlinked text that appears to the user or engine. Anchor text currently holds an enormous influence on many major search engine ranking algorithms. Because of this, it is beneficial to include keyphrases in your anchor text instead of generic phrases.

Applet
A small application, usually in Java, usually for use on the Web.

ArchitextSpider
The name of the Excite search engine's spider.

Ask Jeeves
www.askjeeves.com
A fairly popular search engine. Its claim to fame is that it lets you to enter plain text questions as opposed to only keywords. Ask Jeeves receives search results from Teoma, Overture and ODP.

ASP
Active Server Pages. A server-side scripting language used to deliver dynamic content.

Attribute
A term used in the HTML language to refer to display settings. For example, the "background" attribute inside the tag specifies the background image of a page.

Audience Reach
Refers to the percentage of the total Internet population that use a particular search engine during a given month. Together with search hours, audience reach is an important measure when calculating the popularity of the different search engines.

Authority
Term used to describe a website that is viewed as an expert in it's given field. Authority websites are typically well ranked on major search engines due to their large volume of unique and frequently updated content.

Automated Submission
The practice of machine-based, automatic submission of URLs to search engines, usually with the use of submission software or submission services.

Backlink
A link on another page that links to your webpage. The anchor text of these links is an important factor in SEO. Also called an inbound link.

Bait & Switch
A technique (considered spam) used in SEO. It involves creating an optimized page and a regular page. The optimized page is submitted to the search engines and replaced with the regular page as soon as the optimized page has been indexed.

Banner Blindness
Refers to a "condition" amongst experienced web users who tend to automatically ignore banner ads. Banner blindness is arguably the main cause of low click-through rates in banner advertising.

Beta
A testing stage / testing version of a product. For example, when a beta version of a search engine is released, users can access it online and are encouraged to report bugs and give general feedback.

Bid
In pay per click advertising, you rbid is the amount of money that you are willing to pay for each click derived from a specific keyword search. Minimum bids on PPC engines range from a nickel to a dollar.

Block Level Analysis
A method of analyzing a web page's content on a block-by-block basis, rather than looking at the whole page. It implies that some parts of a page are more important than others, based on what people tend to focus on. Microsoft is said to use block level analysis (BLA) to make its search engine results more relevant.

Blog
The name "blog" is a truncated form of "web log" according to Rebecca Blood's essay "Weblogs: a history and perspective." The term "blog" is used to refer to sites that can best be described as mini-directories, often populated with the site owner's personal favorites and his/her comments. Blogs often contain message boards, chat rooms, articles archives etc.

Bloptimization
Optimization of a blog for search engines.

Boolean Search
A Boolean combination of terms allowing the inclusion or exclusion from search results of documents containing certain words. This is achieved through the use of operators such as AND, NOT and OR.

Broadband
A high-capacity data transmission channel. Broadband access to the Internet allows users to send and receive data at a much higher speed than is possible with a regular phone line. Broadband utilizes the same frequency division multiplexing technique used in cable TV, allowing for the simultaneous transmission of different types of signals.

Broken Link
A link to a page that no longer exists or has been moved to a different URL. Search engine spiders regularly re-spider pages in its index and removes broken links. Most search engines also offer ways for users to report broken links. Broken links can also happen due to errors in HTML coding.

Browser
A program used to display Internet content. Two of the best-known and most widely used browsers are Netscape Navigator and Microsoft Internet Explorer. A newer browser by Mozilla named Firefox is growing in popularity as well. Browsers read coded (HTML, JavaScript etc.) pages and display them as web pages. Browsers typically include features such as bookmarks, back & forward buttons etc.

Browser Compatibility
Referring to the different ways different browsers display the same page. A key consideration in web design (and SEO) is to create pages that are browser independent - in other words pages that work as they are supposed to regardless of the user's choice of browser.

Bug
An error or glitch in a program / search engine.

Burst
A rapid increase in the popularity of a new topic. In the search engine world a burst refers to a significant but usually short-lived increase in both the number of searches done on a specific topic and the number of relevant documents on that topic. Bursts are often related to news stories, new technological advances etc.

Cascading Style Sheets
An add-on to HTML that allows for more accurate control over the way a web page is rendered. CSS allows designers to create custom styles that are then applied to the web site in one of a variety of ways. The main benefit is that something like text colors for an entire site can be changed by editing only the CSS file. CSS can also be used in SEO.

Categorization
The practice of grouping web pages by topic to form a directory.

Category
In the context of Web directories, categories refer to collections of links to sites of a similar topic.

CGI
Common Gateway Interface - a popular interface between web server software and other programs.

Classification
The process of organizing documents available online into topical categories to form directories. These are normally hierarchical tree structures with "Main Categories" and a number of "Sub Categories" which often go several levels deep.

Click Through
Referring to the action of clicking through from, for example, a search engine's results page to a web site. Click through rates are especially useful in Internet advertising where it is an important factor in determining the success of an advertisement.

Click Through Rate (CTR)
Often used in Internet marketing to describe the percentage of users who click on a link or advertisement. The CTR is used as a measure to determine the effectiveness of a link / advertisement. It is most effective if used in conjunction with other measurements like conversion rate.

Click Tracking
Search engines can track user clicks in order to "learn" from users which pages are most relevant to a query. Webmasters may also track clicks through third-party software and/or plugins for your website - using this information to then learn from user trends and pages visited.

Client
A computer, program or process requesting information from a server. Email programs are sometimes called e-mail clients. They request e-mail messages from pop3 servers. Spiders (like Googlebot) and browsers (like Internet Explorer and Netscape) are also clients.

Cloaking
The practice of delivering content based on the IP address of the client. The practice is sometimes defended by saying it's a way of protecting code from theft. It should be noted that the practice of cloaking can get your site banned from the search engines.

Closed Loop
Used to describe a linking structure where a group of web pages interlink heavily while there are few or no links to or from pages outside the group. General consensus is that search engines can detect closed loops and penalize pages in closed loops. It is currently unclear exactly where the cut-off point is. Is it only a closed loop if there are no links to or from pages outside the group or also if there are just too few such links? It is generally advisable to have links to outside pages that in turn also link to many outside pages.

Cluster
Search results grouped together, usually based on a shared top-level domain, to save space on the SERP.

Clustering
A technique the search engines use to group different pages from the same domain in their search results pages. Without clustering, the top spots for certain search terms are often completely dominated by one site. Clusters usually consist of one or two pages from one domain with a link that says something like "More results from jsmcorp.com".

Comment
Comment tags (in HTML) allow the site designer to enter comments explaining the code, making it more understandable for human readers. Comments are not displayed by the browser. Comments are enclosed by the comments tag: . The comment tag is also used to enclose scripts, ensuring that the raw code is not displayed on non-compliant browsers. Comment tags are sometimes loaded with keywords to artificially inflate a page's ranking. Loose that sparkle in your eye though… most search engines ignore comment tags completely.

Content-Based Filtering
Filtering documents by extracting some or all of the content contained in each document. Modern search engines all use content-based filtering in combination with either filtering mechanisms. Best known of these other mechanisms is Google's PageRank system that measures inbound links from other documents.

Conversion Cost
Total cost per sale, calculated by dividing the total cost of an advertising campaign by the number of resulting sales. For example, if $1000 is spent on an advertising campaign and that campaign results in 20 sales, the conversion cost per sale is $50 ($1000 / 20). That means it costs $50 to generate one sale.

Conversion Point
Conversion points are the points at which your customers have completed a specific action on your web site. Common conversion points are: Newsletter sign up - the "thank you for subscribing" page, Order/Sale - the "thank you for your order" page, Download - the "Your download is complete" page.

Conversion Rate (CR)
The percentage of site visitors that deliver the most wanted response (MWR). The CR is an important measure of the effectiveness of the online sales effort. For example, if 4 out of every 100 visitors to a site deliver the MWR, the CR for that site is 4%.

Cost Per Click (CPC)
The 'cost per click' is the amount that you are charged in a pay per click campaign for a specific click and term.

Cost Per Lead (CPL)
The total cost of an advertising campaign divided by the resulting number of new leads.

Counter
Counters count page views, not visitors. The difference is that one visitor can generate many page views by opening many pages on the site. Counters offer a relatively inaccurate way to measure site traffic and are generally considered amateurish. Log files offer far more accurate and comprehensive visitor data.

CPC
Abbreviation for cost-per-click.

CPM
Cost per thousand impressions (M= Roman numeral for 1000). A pricing system often used in the banner advertising industry. Typically a fixed price is offered for 1000 impressions of a banner. The price is usually influenced by the topic of the site (how targeted the audience is) rather than the popularity of the site.

Crawl
What search engine spiders do to gathe rinformation. It refers to the action of following links to navigate from page to page and site to site.

Crawler
A browser-like program that forms part of a search engine. Its task is to "surf" the web by following links from one page to the next and from one site to the next. It collects information from the sites it visits and that information is stored in the search engine's database

Crawler Lag
The delay between the point where a web page is crawled and the point at which it is added to the search engine's index.

Cross Linking
Referring to links between a family of domains - for example your business site, your personal homepage and your cat's homepage. Cross linking is sometimes used to inflate link popularity. Excessive cross linking is widely believed to be penalized by the search engines. Also refers to the link structure of the inside of any given site. In other words, how the site content is distributed and path-driven on the site.

Cybersquatting
The practice of buying domains that contain popular trade names (for example fordmotors.com) or are common misspellings of popular trade names (for example gogle.com). The intent is usually to either resell the domain or to pull traffic through misspellings, rather than to develop a serious, unique site. Traffic gained through misspellings is often automatically redirected to another domain.

Dance
Short for Google Dance.

Data Traffic
Refers to the number of packets of information traversing across a given network.

Database
An electronic filing system containing information that is usually highly organized and categorized. The benefit of electronic filing by means of a database is that specific information can easily be extracted according to given parameters. Search engines are essentially very large, searchable databases. Dynamic web pages typically rely on databases.

Dead Link
A link to a page that no longer exists or has been moved to a different URL. Search engine spiders regularly re-spider pages in its index and removes dead links. Most search engines also offer ways for users to report dead links.

Deep Linking
The practice of linking to the inner pages of another web site - as opposed to linking to the homepage. Although the vast majority of site owners don't mind deep links to their sites, it should be noted that deep linking has potential legal ramifications.

Description
In the context of the search engines, the description refers to the descriptive text accompanied by a title and URL in the search results page. Some search engines take this description from the meta description while most generate their own from the page content. Directories often ask for a description when you submit your page.

DHTML
Dynamic HTML. DHTML is sometimes referred to as the next generation HTML. It gives site designers increased control over the appearance of a site.

Directory
A categorized collection of links to the web, usually compiled manually. Directories can either be general (to the entire web) like DMOZ or Topical like the Dotcom Directory. Although they cannot rival search engines for index size, the generally do offer higher quality search results, arrived at through some editorial selection process.

DMOZ
www.dmoz.org
A massive directory continually expanded by volunteers. What sets this directory apart is that it makes its database of indexed documents available to other directories & search engines. A listing here results in the page automatically being listed in many other directories and search engines. The model of using volunteer editors is fairly ambitious - and surprisingly successful. It is a mammoth achievement and an asset to the online world. Getting a site indexed in DMOZ can be difficult, so be patient.

DNS
Domain Name Service / Domain Name System / Domain Name Server.
Every computer on the Internet has a unique number called the IP address. The IP address is almost like a telephone number, but it's hard to remember everyone's IP address. This is where DNS comes into play. The DNS is a static, hierarchical name service that makes it easier to remember web site addresses by allowing letters (the domain name) to be used instead of numbers. Translating the name back to the IP address is called "resolving" the domain.

DNS parking
A domain is set to be "parked" when it has been registered but not developed into a web site. The registrant pays the annual renewal fees to prevent the domain from falling into someone else's hands. DNS parking is typically done to protect trademarks. Domains registered for resale are usually also parked.

Dogpile
www.dogpile.com
A popular search engine.

Domain / Domain Name
A sub-set of internet addresses. Top-level domains are divided into .com, .net, .org, .biz, .info, .gov and .edu. Apart from these there are also country-specific domain extensions like .ca, .com.au, .co.za, .fr etc. In SEO it is generally accepted that having a keyword-rich domain is beneficial.

Doorway Domain
A keyword-rich domain name used to achieve high search engine ranking for a particular keyword / key phrase. Similar to a doorway page, the doorway domain serves only as a point of entry that leads search engine traffic through to the "real" content of the page. This technique is not advisable. Domains containing only a page or two don't normally rank well on the search engines and spiders typically ignore pages that automatically redirect to other pages.

Doorway Page
Also known as bridge pages, bridging pages, entry pages and landing pages. Referring to a page designed to rank well for a selected keyword and redirect visitors to another, "real" page. Important here is that there are two kinds of doorway pages: those generated automatically based on a template and manually created keyword focused content pages (KFCPs). The first kind is considered spam and penalized by most search engines. The second is an important and usually very effective SEO technique.

Dynamic Content
Web site content generated automatically, usually from a database and based on user actions / selections. Dynamic content typically changes at regular intervals, for example daily or each time the users reloads the page. SERPs are dynamically generated pages, changing depending on user input.

Dynamic Optimization
The practice of adding fields to a database and page templates, like for an ecommerce website, where just as each page has a different product, the optimization elements are also different.

Earning Per Click (EPC)
Earnings Per Click. A unit of measure used to determine a site's ability to convert visitors into customers. Calculated by dividing total sales amount by total page views.

Earnings Per Visitor (EPV)
Earnings Per Visitor. A unit of measure used to determine a site's ability to convert visitors into customers. Calculated by dividing total sales amount by total number of visitors to the site.

Electronic Library
The term normally refers to web sites that provide access to public information like catalogs, e-books, databases, audio files etc.

Exact Match
If not for partial matching, fuzzy matching, collaborative filtering and stemming, search engines would only return exact matches. A search for "power" would only return documents containing the exact term, not documents containing variations or related terms like powerful, strength etc.

Excite
www.excite.com
A major search engine. Currently being provided results from engines across the Internet.
Search Engines: Databases dedicated to gathering Internet Web pages, storing the results and then returning a list of pages that match a user's search. Organic Search Engines: Google, Yahoo and Ask Jeeves
Web Directory Results: About, LookSmart and Open Directory.
Pay-For-Placement Results: Overture, Sprinks and FindWhat.

Expert Document
A document that links to many other (same-topic) documents. Some search engines only consider links from expert documents - as opposed to all documents in the collection - when determining link popularity. According to the Hilltop paper, expert documents are "pages that have been created with the specific purpose of directing people towards resources".

Eye Candy
Aesthetically pleasing web sites are said to provide eye-candy. The term is used to describe sites both positively and negatively. In the context of search engines and SEO, eye candy is generally perceived as unnecessary, not contributing to the marketing effort.

FFA
Free For All. Referring to web pages that contain links to other pages and very little (or nothing) else. The difference between FFA pages and directories is that directories contain links to sites selected through some editorial process, while FFA pages allow anyone to add a link to any page.

Flash
Short for "Macromedia Flash"
A vector graphic animation technology that requires a plug-in but is browser-independent.

Frames
An HTML tag construct that allows designers to display two or more web pages simultaneously. The general perception is that frames can greatly improve site navigation, but they are browser-dependant and not search engine friendly. Most search engines do not index framed pages correctly.

Fresh Crawl
Google updates its entire index of web sites once a month. This is generally referred to as the Google Dance. In an ongoing effort to make their results as relevant as possible, Google introduced a “fresh crawl” that runs each day. The idea behind the fresh crawl is to update pages that change regularly. This allows Google to serve results that are up-to-date with current events.

Fuzzy Matching
Fuzzy matching attempts to improve recall by being less strict but without sacrificing relevance. With fuzzy matching the algorithm is designed to find documents containing terms related to the terms used in the query. The assumption is that related words (in the English language) are likely to have the same core and differ at the beginning and/or end. A search for "matching", for example, would also return documents containing match, matched etc. Unfortunately it will also return documents containing unrelated words like matchbox etc.

Fuzzy Search
A type of search made possible by fuzzy matching. The search engine returns results that it predicts will be relevant, even when the terms used in the query does not appear anywhere in the matched document.

G / GG
In search engine discussion forums, "G" or "GG" is sometimes used as short for Google.

Ghost Site
A site that remains available online but is no longer updated. Ghost sites are not the same as abandoned sites. Ghost sites typically contain some statement explaining that it is no longer being updated, but is not removed because it usually contains information that remains valid / has historic value.

Go.com
www.go.com
Used to be a top search engine, then named "Infoseek". Acquired by Disney, Go.com now simply displays search results from Overture. Also powers large sites such as ESPN.com.

Google
www.google.com
Google is a public and profitable company focused on search services. Named for the mathematical term "googol", Google operates web sites at many international domains, with the most trafficked being www.google.com. Google is widely recognized as the "World's Best Search Engine" and is fast, accurate and easy to use. The company also serves corporate clients, including advertisers, content publishers and site managers with cost-effective advertising and a wide range of revenue generating search services. Google's breakthrough technology and continued innovation serve the company's mission of "organizing the world's information and making it universally accessible and useful."

Google bomb / Google bombing
The practice of using anchor text to make a page show up in the SERPs under keywords that are out of context for that page. For instance, if you want your arch enemy's page to be #1 on Google for "absolute moron", you'd get as many people as possible to link to his page using "abosute moron" as anchor text. Google bombing can of course also be used to create a positive effect. In theory you could get your own site listed at the top for very targeted keywords using the same technique. Both these uses are of course aimed at manipulating search results and as such are spam.

Google Dance
Google utilizes several datacenters from which it draws its results. The 'Google Dance' refers to users drawing different results from different locations based on some datacenters having more up to date content. This dance has been the scourge of SEO professionals for as long as Google has been at the top of the search engine wars.

Googlebot
Google's spider.

Googlewhacking
The name of a "Google game". Google has an immense database. The aim is to enter a query consisting of two words (without using quotes) that returns only one result from the database. The words must both be in the dictionary (if they are they will be underlined at the top of your search results). If you see "Results 1-1 of 1", you've got yourself a Googlewhack.

Hand Submission
The practice of visiting each search engine and directory and submitting the registration form by hand as opposed to using a software program. Some systems will not accept automated submissions.

Heading / Header Tag
<H1></H1>, <H2></H2> etc., with H1 being the largest. Heading tags have significance in SEO. Search engines normally assign more weight to documents where the keywords used in the query are found inside heading tags. Pages that use heading tags generally rank higher, but excessive use might get the page de-listed.

Hidden Text
Text on a web page designed to be visible to spiders but not to human visitors. The aim is to load the page with keywords without deterring from the visitor's experience. Of the various techniques of hiding text, the most common is to set the text color to exactly or nearly the background color. Most search engines can now detect hidden text and consider it a form of spamdexing. Pages that contain hidden text are penalized or even de-listed.

Hit
One hit is one request for a file on a web server. A visitor opening a page with 5 images will in the process generate 6 hits (1 each for the images and one for the HTML page itself). The term is sometimes also used with reference to the number of results (hits) a search engine returns for a specific query. Hits are often confused with page views and unique visitors.

HITS
Hyperlink Induced Topic Search. Referring to a search where the search algorithm relies (partly) on hyperlinks to identify topic areas. Not to be confused with "hits" referring to file requests.

Homepage / Home Page / Home
The main "index" page or navigation hub of a web site. The homepage is not necessarily the first page. Many sites use splash pages to welcome visitors and lead them from there to the homepage. At most search engines you can simply submit your homepage and leave it to the spider to crawl the rest of the site from there.

Hot Linking
The practice of displaying images files, video files etc. on a web site when those files are on another (usually someone else's) server. Effectively the site displays content that uses up someone else's bandwidth. Hot linking is generally considered unethical unless prior permission is obtained.

HTML
Hypertext Markup Language. HTML is the primary language used to create web sites.

HTTP
Hypertext Transfer Protocol. HTTP is the most common transfer protocol used to facilitate communication between servers and browsers.

Hub
Coined by Jon Kleinberg during the development of his HITS algorithm. Hubs are sites that link to many other sites that are cosidered authorities in their topic area. For instance, the Ford Motor Company's web site is an authority in the car manufacturing topic. So is Ferrari's web site etc. A site that links to all these manufacturers would be considered a good hub within the car manufacturing topic.

Hyperlink
Clickable content on a web page usually leads to another page, another site or another part of the same page. The clickable content therefore is said to link to the other page / site / part of the same page. Spiders use links to crawl from one page to the next as they index web sites.

iBL / ibl
Short for inbound link.

Image Map
An image that has different clickable areas linked to different pages. Image maps can either be imbedded in the HTML code or called as an external file. Search engines usually have difficulty spidering image maps when they are included from external files.

Impression
One display of an image or advertisement.

Inbound Link
When site A links to site B, site A has an outbound link and site B has an inbound link. Inbound links are counted to determine link popularity, an important factor in SEO.

Index
Referring to the searchable database of documents stored by a search engine - often simply referred to as a search engine's database. When used as a verb, it describes the process of converting a collection into a searchable database. The term is sometimes also used to refer to directories like ODP.

Index File
A file created by a search indexer program, designed to store information in a format that makes fast retrieval possible.

Information Extraction
A field of study related to information retrieval that attempts to identify semantic structures in order to extract relevant data.

Information Retrieval
A field of study related to information extraction. Information retrieval is about developing systems to effectively index and search vast amounts of data.

Infoseek
infoseek is the old name for the Go.com search engine. Go.com was acquired by Disney and started displaying results from Overture, a PPC search engine. At the moment it displays results from Google.

Inktomi
A large database of web sites, started in 1996, that feeds results to some search engines. Inktomi also provides a range of other services, including content networking solutions, search solutions and wireless solutions.

Intranet
Essentially a web site or group of (usually interlinked) web sites that is only accessible to people within a specific group or organization. Most large companies have intranets. Intranets offer a safe place for employees to publish information that improves workflow. Intranets typically house shared applications, internal telephone and e-mail directories, rules and regulations, help files etc. Many large intranets have a search facility that allows users to find specific information more easily.

Invisible Text
Text on a web page that is exactly or almost the same color as the background. The use of invisible text to load a page with keywords was once a popular SEO technique, but search engines can now detect invisible text and penalize sites that use it. Although there are examples of sites that use invisible text and "get away with it" on Google, the general consensus is that it is not worth the risk. The same results can usually be achieved by working the keywords into the visible body text.

IP
Internet Protocol. Essentially a set of standards that are necessary to ensure that data sent between networks are readable on both sides. IP provides the standard for the way data is scrambled and sent over the Internet, while TCP (transmission control protocol) provides a standard for the way data is unscrambled. These two standards are essential to the working of the Internet.

IP address
Every Internet user and every server has a numeric address. Something like 123.45.67.890. IP addresses provide essential identification online. Domain names can be set up to have a unique IP address, something that is useful in SEO.

IP Spoofing
A controversial technique for reporting a false IP address. In the context of search engines, IP spoofing is sometimes used to refer to the practice of cloaking.

Java
A powerful, platform-independent programming language. In other words, Java can be used to create advanced programs that can be run on different computers with different operating systems. Java is also used extensively to create applets for use on the web.

JavaScript
A comparatively simple scripting language used extensively on the web to, amongst other things, make web pages interactive. JavaScript shares characteristics of Java, but it is less complex and less powerful. One of the main benefits of JavaScript is that it can seamlessly integrate with HTML.

Kanoodle
A comparatively small, but growing rapidly, search engine that uses the PPC model.

Keyword
A word used in a query. In SEO, pages are typically optimized for specific keywords. Keywords are targeted based on what users looking for the specific information or product are most likely to use as part of a query. Accurate keyword targeting is considered by most to be essential to effective SEO.

Keyword Density
A measure of the percentage of words on a page that are specifically chosen keywords. When a user enters a query, search engines display a list of pages containing the search terms. These are ranked based on (amongst many things) the percentage of words on a page that are similar to the words used in the query (keyword density). When keyword density is inflated artificially, it is often referred to as keyword stuffing.

Keyword Stuffing
Excessive repetition of keywords in an attempt to artificially inflate keyword density and improve a page's ranking. Keyword stuffing is easily detected by search engines and pages that use this technique are penalized.

Keyword Tag/ Keywords Tag
A meta tag listing keywords associated with the page. Formerly effective, now ignored by Google and most major engines.

Keyword Targeting
The practice of optimizing certain pages of a web site to rank well in a search for specific keywords. Keyword targeting is generally considered vital to effective SEO.

Kickback Marketing
A collective name for post-dotcom-bust Internet marketing techniques that focus on revenue sharing. Examples of kickback marketing include affiliate programs, pay-for-performance programs, bartering etc. The success of kickback marketing lies in its utilization of the nature of the Internet to effortlessly pass customers back and forth between affiliated sites.

Lead
A typical MWR, mostly referring to a potential customer's contact details. Many companies don't sell online but rather use their sites to generate leads that are then followed up. Many affiliate programs also reward affiliates on a per-lead basis rather than a per-sale basis.

Link / Hyperlink
Clickable content on a web page usually leads to another page, another site or another part of the same page. The clickable content therefore is said to link to the other page / site / part of the same page. Spiders use links to crawl from one page to the next as they index web sites.

Link Checker / Link Validator
A program that scans web sites for dead links. Most link checkers generate reports that list all dead links on a site. This is effective to ensure proper search engine spidering.

Link Farm
Similar to FFA pages, it refers to a page where anyone can list a web site to be linked to. Link farms are used to artificially boost link popularity. Most search engines penalize sites associated with link farms.

Link Popularity / Linkage
A measure of the quantity and quality of inbound links. Link popularity is an important factor in SEO.

Link Swap / Link Exchange
Similar to reciprocal links, referring to the practice of two or more sites exchanging links in an effort to boost link popularity.

Link Text
See anchor text

Link Tracking
A type of indexing designed to track inbound links to a document. Many search engines offer ways to easily track inbound links. At Google, for example, simply type "link:www.your-domain-here.com" (without the quotation marks) for a list of sites linking to www.your-domain-here.com.

Log File
Each web site has a log file (stored on the server), which records details every time a visitor to the site requests a file. Log files store data such as the IP address of the visitor, the visitor's nationality, operating system, browser etc. The log file can be analyzed to obtain statistics on unique visitors, page views, hits etc., which are often used as measurements in SEO.

Log File Analysis
Referring to the analysis of records stored in the log file. In its raw format, the data in the log files can be hard to read and overwhelming. There are numerous log file analyzers that convert log file data into user-friendly charts and graphs. A good analyzer is generally considered an essential tool in SEO because it can show search engine statistics such as the number of visitors received from each search engine, the keywords each visitors used to find the site, visits by search engine spiders etc.

Looksmart
www.looksmart.com
A comparatively small directory.

Lycos
www.lycos.com
Lycos started out as a search engine and was very highly rated in the late 90's. Today, web search remains one of its features, but there has been a shift of focus to become a more general portal site with features like e-mail, personalization etc.

Manual Submission
The process of manually submitting a web page to a search engine or directory as opposed to using submission software or a submission service. Manual submission is considered by many to be the only reliable form of submission, although some programs and services have begun distinguishing themselves as viable options.

Match
A match occurs when a document in the search engine's index contains terms entered as part of the query. The matching documents, simply called matches, are then displayed on the SERP. It's worth noting that search engines have different criteria for deciding when a document is a match. Most search engines only require that one word in the query match one word in the document. Some search engines (like Google), require all words to appear in the document before that document is considered a match.

META Description Tag
An HTML tag that gives a general description of the contents of the page. This description is not displayed on the page itself, but is largely intended to help the search engines index the page correctly. Some search engines use the description found in the description tag on their SERPs. A growing number of search engines are completely ignoring the description tag.

Meta Refresh
An HTML tag that is used to reload or refresh the page after a specified interval, often use to automatically redirect visitors to another page. Most search engines penalize pages that use meta refresh or any other type of automatic redirection.

Meta Search
A search performed on a meta search engine. MetaSearch is also the name of a meta search engine found at www.metasearch.com.

Meta Search Engine
A type of search engine. Meta search engines usually do not maintain databases. Instead, they query other search engines' databases and return results from all of them - usually with a mention of the search engine next to the each result.

Meta Tag
An HTML tag placed in the head section of a web page. The tag provides additional information that is not displayed on the page itself. The initial idea was that webmasters should use these tags to help search engines index the page correctly by providing an accurate description of the page content and a list of keywords associated with the page. Unfortunately this left the door open to abuse. Many webmasters used these tags to gain an unfair advantage, forcing search engines to begin disregarding meta tags.

Metacrawler
www.metacrawler.com
A popular meta search engine.

Mirror Sites
Referring to sites that offer authorized duplicates of content also found on other sites. The initial motivation was to ease bandwidth load and increase availability by distributing popular files to many servers. In the context of SEO, the term is mostly used to refer to sites that attempt to deceive search engines into indexing more than one instance of a site by duplicating it on another server and domain. Most search engines now have filters in place to detect mirror sites and many of them penalize these sites by de-listing both the original site and the mirror site.

Most Wanted Response (MWR)
A term coined by Ken Evoy, referring to the aim of a web site, for example, to generate a sale or to get the visitor to subscribe to a newsletter.

Mozilla
An early, open-source web browser. Many pro-surfers feel that there are far fewer bugs when using Mozilla's FIrefox browser as opposed to Microsoft's Internet Explorer.

Natural Language Processing (NLP)
A system that allows search engine users to type a question rather than keywords. There are a couple of ways to do this kind of processing. At the simplest level, the search engine simply removes the stop words in the question to leave keywords that are then processed as if it was a regular query. At the other end of the scale are very advanced systems that use statistics and linguistic analysis to accurately match documents to the user's question. The best-known example of this kind of approach is the AskJeeves search engine.

Natural Linking
Describes the hypertext links found on web sites that are part of text content and that link to expanded or additional information on a subject without consideration of their value in link popularity.

Netscape Navigator
An early web browser, based on the Mosaic model and developed by the Netscape company - as they were then known. The browser is still around today, available from www.netscape.com. It's popularity declined rapidly after Microsoft steamrollered the browser scene (about 1997) by starting to bundle their Internet Explorer browser with Windows.

Newsgroup
A discussion forum where users can post messages and reply to other users.

Obfuscation
A rarely-used term, more often called spamdexing. It refers to the misrepresentation of meta tags and page content in order to gain an unfair advantage in the search engines. The term is sometimes differentiated from spamdexing in that it is used to refer to pages that, through stealth, rank highly although they are poorly optimized. The idea is to deliberately mislead others who might steal the page.

ODP (Open Directory Project) / DMOZ
www.dmoz.org
A massive directory continually expanded by volunteers. What sets this directory apart is that it makes its database of indexed documents available to other directories & search engines. A listing here results in the page automatically being listed in many other directories and search engines. The model of using volunteer editors is fairly ambitious - and surprisingly successful. It is a mammoth achievement and an asset to the online world. Getting a site indexed at ODP can be difficult

Off the Page / Off Page Factors
Those factors that impact the ranking of a web page but that are not located on the web page itself. Inbound links, anchor text etc. are examples of off the page factors.

Operators
"AND", "NOT" and "OR" as used in Boolean Searching.

Optimize / Optimization
A webpage is said to be optimized when it has been structured in such a way that it ranks well (on the SERPs) for those keywords it targets. It is a fairly subjective concept. What some see as optimization might be termed spamdexing by others. In the strictest sense, optimization means simply making a page spider-friendly by, for example, using text links rather than image links. In the SEO industry the term is more often used as a collective name for all the "tricks" webmasters use to improve a page's ranking.

Outbound Link
When site A links to site B, site A has an outbound link and site B has an inbound link.

Overture
www.overture.com
Close to Google AdWords as the largest and most popular of the PPC (pay-per-click) search engines. Formerly known as Goto.

Packet Sniffing
The practice of monitoring pieces of data (called packets) as they move over the Internet.

Page Jacking / Pagejacking
The act of duplicating a (usually high ranking) web page and presenting the duplicate as the original. This kind of blatant theft is fairly uncommon. In most cases the legitimate author / owner can easily prove ownership of the material.

PageRank
Google's measure of the link popularity of a page. Rated on a scale of 1-10, PageRank can have an enormous impact on SERP placement.

Partial Word Matching
Some search engines will consider not only exact matches, but also partial matches. This means that if the search term is contained within a word in a document in its index, the search engine considers the document a match. It's not as complicated as it sounds though. If the user enters "word" as the query, the search engine will consider a document a match if it contains word or wordiness or foreword or MSWord etc. So the search term should be contained in the word.

Pay Per Click
See PPC

Phrase Search
A search for documents containing an entire phrase - as opposed to one or more keywords. The important distinction here is that in a phrase search, the words has to appear side by side in the document (exactly as in the query) for that document to be considered a match. If the words appear scattered or they appear side by side but in the wrong sequence, it is not considered a match. Phrase searching can be done on most search engines by simply enclosing the phrase in quotation marks.

Pop-Under / Popunder / Pop Under
A supposedly less annoying variation of the pop-up. It creates a new browser window, usually containing an advertisement that is displayed behind the current window. The user then only sees the pop-under when the current window is closed or minimized. In truth, many users find pop-unders as annoying as pop-ups, with the added irritation of feeling tricked into not closing the new window immediately.

Pop-Up / Popup / Pop Up
A new browser window (usually containing an advertisement) automatically opened when the users performs a specified action - like opening a page, clicking a link, closing a page etc.

Portal
A web site that functions as a kind of starting page or entry point to the web. Portals typically have a wide variety of features such as search, free web-based e-mail, news etc. Well-known examples include Excite and Yahoo.

PPC
Pay-Per-Click. An advertising payment model where the advertiser pays only when the advertisement is actually clicked. In other words, the advertiser literally pays only for visitors rather than per advertisement impression. The term CPC (cost per click) is sometimes used in the place of PPC and the plural PPCs is sometimes used to refer to PPC search engines.

PPC Advertising
Abbreviation for pay-per-click advertising.

PPL
A system where the receiving site pays a certain amount to the referring site for every new lead.

PPV
Pay per visit. Same as PPC only the term "visit" is used instead of "click".

PR0 / PR zero
PageRank zero. A penalty (rumored to be) imposed by Google on sites caught spamdexing. It's worth noting that Google denies having such a penalty.

Precision
Search engines will often consider a document a match to a query when that document is not really relevant to the query. These mistakes happen because search engines, to a certain extent, have to "guess" what the user is looking for - especially when words used in the query have double meanings. Search engines must find a balance between recall (it's ability to find all relevant documents) and precision (it's ability to find only relevant documents). The aim in information retrieval is to get both recall and precision spot-on. In other words to return all relevant documents and nothing else. In the real search engine world however, it is often a trade-off. Precision is scored by dividing the total number of pages found by the number of relevant pages found. For example, if 1000 documents are found and 770 are relevant, the search engine's precision is 0.77 or 77%.

Promotion
In the context of search engines it refers to submitting of the site information with the intent of getting the search engine to list the site.

Query
A keyword, group of keywords or phrase, with or without special instructions like Boolean operators, used in a search. In simpler terms, it is that which the user enters into the search box. It is what the search engine compares documents to in order to return only relevant documents.

Quote(s)
When used in a search, the quote marks ' " ' tell most systems that you only want to see matches that are exactly like what you are asking for. For example, a search for 'electric light', entered without the single quotes, will return much different results than "electric light" entered with the quotes as shown.

Ranking
Referring to the position of a web page on the search results for a particular query. For example, a page that is listed third for the term "bubblegum" is said to have a ranking of 3 for that term.

Reciprocal Link
A link placed on site A, pointing to site B, on the condition that site B returns the favor. Also called a link swap. Contrary to popular belief, reciprocal linking does not necessarily improve a site's PageRank. In some cases it can have a negative effect on PageRank.

Redirect
Users can be redirected from one page to another either by asking them to click on a link or by means of automatic redirection, most often done with the meta refresh tag. Automatic redirection has been misused to the point where most search engines now penalize sites that use it, typically by de-listing the offending site.

Referrer
When a user follows a link from page A to page B, page A is called the referrer. The referrer is identified by the URL of the referring page. Referrer information can be accessed through the log file.

Relevance / Relevancy
The measure of the accuracy of the search results - in other words it's a measure of how close the documents listed in the search results are to what the user was looking for. The ability to return relevant results is a big thing in the search engine world - and arguably the one thing that made Google stand out of the crowd and gain much popularity in a short time.

Robot
A browser-like program that automatically request web pages in order to index the page content (in the case of spiders) or to retrieve specific information (in the case of programs like e-mail harvesters).

Robots.txt / Robots Text File
A text file (with the ".txt" extension) that tells spiders which pages it may not index. Every time a spider (that complies with the Robots Exclusion Standard) visits a site it will first request a robots.txt file to see where in the site it is not allowed to go

ROI
Return On Investment. In the context of SEO, the term refers to sales generated as the direct result of a search engine marketing campaign.

Script
A piece of programming designed to perform a certain function on a web page - for example to create a rollover effect on buttons or to create pop-ups.

Search
The process of locating information - on the Internet typically done by searching through documents in search engine and directory databases.

Search Engine
A tool for finding information on the Internet. Most search engines consist of the following main components:
1. Spider
2. Indexer
3. Database
4. Search software
5. Web interface
Documents found by the spider are processed by the indexer and stored in a database. From the database the search software extracts documents based on parameters entered by the user. Examples of search engines include Google and AllTheWeb. Directories like Yahoo and ODP are often referred to as search engines although they are not.

Search Engine Marketing
See SEO

Search Engine Optimization
See SEO

Search Results
The documents returned by a search engine in response to a query.

Search Term(s)
Words entered into a search engine's search box to form a query.

SEO
Abbreviation for Search Engine Optimizer or Search Engine Optimization

SEO
Search Engine Optimization. This term is widely used in the search engine industry as a collective name for those activities that are directly or indirectly aimed at improving a page's search engine ranking. Sometimes the term SEO is also used to refer to providers of SEO services - in other words it's used in the place of terms like "SEO provider" and "SEO specialist".

SERP(S)
Search Engine Results Page(s). The term refers to the page of search results a search engine displays in response to a query.

Similarity
The measure of the degree to which a document matches a query or the degree to which two or more documents are alike.

Site Search
A search utility that allows the user to search through documents on a particular site. Different from a search engine in that it's database contains only documents found on that site as opposed to a wider collection of documents from all over the web.

Sitemap
A map to your site. A sitemap contains links to every page of your site (check out Google's sitemap). The important benefit of having a sitemap (apart from helping your visitors find what they are looking for) is that spiders can find all pages on a site quickly and with fewer hops. For maximum benefit, insert a prominent link to your sitemap on every page of your site.

Slurp
Inktomi's spider.

Snippet
Referring to the quoted pieces of page content search engines like Google use on the SERPs instead of a traditional, webmaster created site descriptions. The term originates from the "NOSNIPPET" robots meta tag used to disallow SNIPPETS.

Spam
A collective name for those marketing techniques that are intrusive, offensive and/or unethical in some way. A major characteristic is that it aims its message at a wide (often in the millions), untargeted audience - which it can afford because electronic distribution is very cheap. The most common form of spam is unsolicited commercial e-mail. In the search engine world, regular mass submission of web pages to search engines is also referred to as spam or spamdexing. The term spamdexing is also used to refer to all SEO techniques that are deceptive or unethical.

Spider / Spyder
A browser-like program that forms part of a search engine. Its task is to "surf" the web by following links from one page to the next and from one site to the next. It collects information from the sites it visits and that information is stored in the search engine's database.

Spidering
What spiders do - the process of surfing the web and indexing documents.

Splash Page
A page that is displayed before users enter a site. Splash pages are often comparatively empty except for a logo, welcome message and "click here to enter" type of link. Splash pages are often used to house introductory Flash animations. Splash pages are generally considered annoying since they offer very little value. Even very impressive splash pages offer only entertainment - which normally distracts from the sales effort and hampers SEO.

SSI (Server Side Include)
A type of HTML command that allows webmasters to insert code from an outside HTML document. It is especially used with things like menus, headers and footers that are the same for all pages. To change the menu, for example, the webmaster changes only the external menu file and the menu changes across the entire site. SSI can also be used to insert non-HTML elements like scripts.

Stats / Statistics
In the context of search engines, the term is often used to refer to the information created by some type of reporting software. The web server log files for the site are used as the source of the information. Also known as Web stats, web reporting, statistics, and traffic reports. Stats typically include information like number of visitors, referring URLs, search engine queries used, number of page views etc.

Stemming
The use of linguistic analysis to get to the root form of a word. Search engines that use stemming compare the root forms of the search terms to the documents in its database. For example, if the user enters "viewer" as the query, the search engine reduces the word to its root ("view") and returns all documents containing the root - like documents containing view, viewer, viewing, preview, review etc.

Stop Word
Words like conjunctions, prepositions etc. that are so commonly used that they have little or no influence on relevance. Most search engines ignore stop words entered in a query.

Sub-category
Directories are typically divided into top-level categories that contain sub-categories or lower level categories. Directories often run several category levels deep.

submission
The process of manually adding a URL to a search engine's list of URLs to spider - in effect telling a spider about a page in order to get it spidered and ultimately added to the search engine's database.

Submission Service
Services exist where the user can have pages submitted to multiple search engines for a fee. The fee is normally very low, but usually not as low as the quality of the submission.

Submission Software
Programs that assist webmasters in optimizing and submitting web pages to search engines. There are countless programs available, but probably only a handful that are worth getting.

Throwaway Domain
A domain where the name itself has little value to the owner. Throwaway domains are typically used to experiment with. It's common among search engine spammers to rigister throwaway domains to experiment with things like cloaking. Unethical SEO providers sometimes use throwaway domains to build link popularity to a client's site. This can backfire though as search engines are continually finding better ways to combat spam. It's worth noting that Google specifically warns against the use of throwaway domains. See their information for webmasters for details.

Title
The title of a page is displayed in the title bar right at the top of the browser window. Almost all search engines consider the title when determining a document's relevance to a query and most search engines consider the title the most important element. In the page, the title is specified as an HTML element and placed in the header section of the page.

TLD
Top Level Domain. See domain.

Toolbar
With reference to search engines, toolbars are browser add-ons provided by the search engines. These toolbars often include a search box, shortcuts to the different sections of the search engine, additional page information etc.

Top-Level Page
Some search engines call your default page (usually something like index.html, index.htm, default.asp etc.) your top-level page. When they say "submit only your top-level page", it means that they probably have a spider that will find the rest of your pages from there. It's always a good idea to have a link from your top-level page to your sitemap.

Traffic
Often used as a synonym for "visitors". The term is used to describe activity on a web site - be it hits, page views or unique visitors.

Unique Visitor
Used to describe one person visiting a site. That one person may generate multiple visits over a period of time, therefore log files normally show more visits than unique visitors. The shortened version "uniques" is sometimes used to refer to unique visitors.

Upload
The process of transferring information from a local drive to a server - specifically when that information then becomes accessible via the Internet.

URL
Uniform Resource Locator / Universal Resource Locator. A unique Internet address (for example http://www.jsmcorp.com) that every Internet resource must have in order to be located.

Variable / URL Variable
Refers to information that is passed to the server with the URL that the server uses within the context of a script or server-based program.

Virtual Domain
A domain that is hosted on a virtual server. The domain is unique, but the IP address is normally shared with other domains. This has some implications for SEO.

Virtual Server
When a domain is hosted on a virtual server, it means that it shares that server with other domains. This is a very cost effective way of hosting web sites, but access speeds are not as high as for domains hosted on dedicated servers.

Visitor
The term is sometimes confused with unique visitor. The difference is that one unique visitor visiting a site repeatedly over a period of time will show up on the site's log file as many visitors. The term therefore refers to the number of times people visit a site - not the actual number of people visiting a site.

Wayback Machine
Waybackmachine.org
A very large "archive" of the web. The Wayback Machine stores "snapshots of sites", allowing users to have a look at how sites looked "wayback" then.

Web Copywriting
Copywriting specifically aimed at an online audience. It shares many of the ground rules of offline copywriting, but has quickly evolved to become a stand-alone science. Recently it has also begun taking into account how spiders see web pages. Although there are many who feel copywriters should focus on converting visitors to customers and not be concerned with getting visitors, there are strong arguments for SEO considerations to form part of web copywriting.

WHOIS
A type of search where the query is a domain name and the result shows details of the domain, like when it was registered, by whom, when it expires etc.

XML
Extensible Markup Language. A web programming language that allows web authors to define their own, custom tags. Especially useful in the creation of web-based applications.

Yahoo!
Yahoo.com
One of the first and most-loved web directories, Yahoo is presently (2002) believed to be the most visited site on the Internet.

Zone
Some search engines allow users to limit a search to specific zones - better described as topic areas. A user may, for example, elect to search only documents from a certain geographic area or only documents created within a specific timeframe.