SEO Glossary A - H

301 - Moved Permanently

A webpage has been moved permanently to a new location.

A way of telling Search engines that a webpage has moved to a new location. Two benefits:

1. 1. The Search Engine will not try to keep re-indexing and getting errors from the old page location.
2. 2. The Search Engine can quickly locate and index the new page.

404 Not Found - The server was unable to locate the web page.

This is an error that the search engines (and browsers) will receive when a page is missing. Usually because of an incorrect link, or the page has been deleted or moved.

Fix this problem: 

1. 1. Make sure your webmaster creates a custom 404 page so that users and search engines can still navigate to other areas of your site.
2. 2. If the page has moved, have your webmaster create a 301 Redirect to the new location.
3. 3. Check that the links to the page are correct.

Absolute Link or Absolute URL

An absolute link or URL is the full link to your website such as http://www.seoukexpert.com/index.php?page=choosing-your-keywords 

AllTheWeb

Search engine which was created by Fast, then bought by Overture, which was bought by Yahoo. Yahoo may use AllTheWeb as a testing area for new features and search techniques.

Alt Attribute

Should be used in an <img> tag to describe the image. Blind people and most major search engines are not able to easily distinguish what is in an image. Using an image alt attribute allows you to help screen readers and search engines understand the function of an image by providing a text equivalent for the object.

Very effective for SEO use.

AltaVista

Search engine bought out by Overture prior to Overture being bought by Yahoo. AltaVista was an early authority in search, but on October 25, 1999 they did a major algorithmic update which caused them to dump many websites. Ultimately that update and brand mismanagement drove themselves toward irrelevancy and a loss of mindshare and marketshare.

Amazon.com / Amazon.co.uk

Amazon (the online bookstore) also owns a number of other popular search tool websites, including IMDB and Alexa.

Analytics

Websites and software which helps you track visitors to your website. More information on this can be found it our Reporting section.

Anchor Text

The text that is clicked on to follow a link (hyperlink). If the link is an image the image alt attribute may act in the place of anchor text.

More info on Anchor Text can be found in our links section.

AOL

America OnLine - Internet Serive Provider. Search results from Google.

ASP / ASP.net 

Programming language by Microsoft used to create dynamic webpages. usually to link webpages to a database and CMS (Content Management System). The file extension of ASP or ASP.NET pages is usually .asp or .aspx

Ask (Ask Jeeves)

Ask is a search engine owned by InterActive Corp. They were originally named Ask Jeeves, but they dumped Jeeves in early 2006. Their search engine is powered by the Teoma search technology, which is largely reliant upon Kleinberg's concept of hubs and authorities.

Ask Sponsored Listings  

Ask syndicates AdWords ads, but also sells internal pay per click ads as well
Ask Webmaster Help

Authority

The ability of a page or domain to rank well in search engines. Five large factors associated with site and page authority are link equity, site age, traffic trends, site history, and publishing unique original quality content.
Search engines constantly tweak their algorithms to try to balance relevancy algorithms based on topical authority and overall authority across the entire web. Sites may be considered topical authorities or general authorities. For example, Wikipedia and DMOZ are considered broad general authority sites. This site is a topical authority on SEO, but not a broad general authority.

Authorities

Topical authorities are sites which are well trusted and well cited by experts within their topical community. A topical authority is a page which is referenced from many topical experts and hub sites. A topical hub is page which references many authorities.
Example potential topical authorities:

the largest brands in your field
the top blogger talking about your subject
the Wikipedia or DMOZ page about your topic

Automated Bid Management Software

Pay per click search engines are growing increasingly complex in their offerings. To help large advertisers cope with the increasing sophistication and complexity of these offerings some search engines and third party software developers have created software which makes it easier to control your ad spend. Some of the more advanced tools can integrate with your analytics programs and help you focus on conversion, ROI, and earnings elasticity instead of just looking at cost per click.

B

Backlink (see Inbound Link)

Bait and Switch

Marketing technique where you make something look overtly pure or as though it has another purpose to get people to believe in it or vote for it (by linking at it or sharing it with friends), then switch the intent or purpose of the website after you gain authority.
It is generally easier to get links to informational websites than commercial sites. Some new sites might gain authority much quicker if they tried looking noncommercial and gaining influence before trying to monetize their market position.

Banner Blindness

A phenomenon whereby users become 'blind' to banner ads as they know where to expect them and ignore that area of the page. As the adverts and paid links become more sophisticated, so do the users. Users also tend to click more on organic search results than on the sponsered listings.

Bias

Search engines may bias there search results toward non-commercial orginisations.

Black Hat SEO

Search engines set up guidelines that help them extract billions of dollars of ad revenue from the work of publishers and the attention of searchers. Within that highly profitable framework search engines consider certain marketing techniques deceptive in nature, and label them as black hat SEO. Those which are considered within their guidelines are called white hat SEO techniques. The search guidelines are not a static set of rules, and things that may be considered legitimate one day may be considered deceptive the next.
Search engines are not without flaws in their business models, but there is nothing immoral or illegal about testing search algorithms to understand how search engines work.

People who have extensively tested search algorithms are probably more competent and more knowledgeable search marketers than those who give themselves the arbitrary label of white hat SEOs while calling others black hat SEOs.

When making large investments in processes that are not entirely clear trust is important. Rather than looking for reasons to not work with an SEO it is best to look for signs of trust in a person you would like to work with.

Block Level Analysis

A method used to break a page down into multiple points on the web graph by breaking its pages down into smaller blocks.
Block level link analysis can be used to help determine if content is page specific or part of a navigational system. It also can help determine if a link is a natural editorial link, what other links that link should be associated with, and/or if it is an advertisement. Search engines generally do not want to count advertisements as votes.

Blog

A periodically updated journal, typically formatted in reverse chronological order. Many blogs not only archive and categorize information, but also provide a feed and allow simple user interaction like leaving comments on the posts.
Most blogs tend to be personal in nature. Blogs are generally quite authoritative with heavy link equity because they give people a reason to frequently come back to their site, read their content, and link to whatever they think is interesting.

The most popular blogging platforms are Wordpress, Blogger, Movable Type, and Typepad.

Blog Comment Spam

Either manually or automatically (via a software program) adding low value or no value comments to other sites.
Automated blog spam:

Nice post!
by
Discreat Overnight Viagra Online Canadian Pharmacy Free Shipping
Manual blog spam:

I just wrote about this on my site. I don't know you, but I thought I would add no value to your site other than linking through to mine. Check it out!!!!!
by
cluebag manual spammer (usually with keywords as my name)
As time passes both manual and automated blog comment spam systems are evolving to look more like legitimate comments. I have seen some automated blog comment spam systems that have multiple fake personas that converse with one another.

Blogger

Blogger is a free blog platform owned by Google.
It allows you to publish sites on a subdomain off of Blogspot.com, or to FTP content to your own domain. If you are serious about building a brand or making money online you should publish your content to your own domain because it can be hard to reclaim a website's link equity and age related trust if you have built years of link equity into a subdomain on someone else's website.

Blogger is probably the easiest blogging software tool to use, but it lacks many some features present in other blog platforms.

Bookmarks (Social Bookmarks)

Most browsers come with the ability to bookmark your favorite pages. Many web based services have also been created to allow you to bookmark and share your favorite resources. The popularity of a document (as measured in terms of link equity, number of bookmarks, or usage data) is a signal for the quality of the information. Some search engines may eventually use bookmarks to help aid their search relevancy.
Social bookmarking sites are often called tagging sites. Del.icio.us is the most popular social bookmarking site. Yahoo! MyWeb also allows you to tag results. Google allows you to share feeds and / or tag pages. They also have a program called Google Notebook which allows you to write mini guides of related links and information.

There are also a couple meta news sites that allow you to tag interesting pages. If enough people vote for your story then your story gets featured on the homepage. Slashdot is a tech news site primarily driven by central editors. Digg created a site covering the same type of news, but is a bottoms up news site which allows readers to vote for what they think is interesting. Netscape cloned the Digg business model and content model. Sites like Digg and Netscape are easy sources of links if you can create content that would appeal to those audiences.

Many forms of vertical search, like Google Video or YouTube, allow you to tag content.

See also:

Del.icio.us - Yahoo! owned social bookmarking site
Yahoo! MyWeb - similar to Del.icio.us, but more integrated into Yahoo!
Google Notebook - allows you to note documents
Slashdot - tech news site where stories are approved by central editors
Digg - decentralized news site
Netscape - Digg clone
Google Video - Google's video hosting, tagging, and search site
YouTube - popular decentralized video site

Boolean Search

Many search engines allow you to perform searches that contain mathematical formulas such as AND, OR, or NOT. By default most search engines include AND with your query, requiring results to be relevant for all the words in your query.

Brand

The emotional response associated with your company and/or products.
A brand is built through controlling customer expectations and the social interactions between customers. Building a brand is what allows you to move away from commodity based pricing and move toward higher margin value based pricing.

Branded Keywords

Keywords or keyword phrases associated with a brand. Typically branded keywords occur late in the buying cycle, and are some of the highest value and highest converting keywords.
Some affiliate marketing programs prevent affiliates from bidding on the core brand related keywords, while others actively encourage it. Either way can work depending on your business model and marketing savvy, but it is important to ensure there is synergy between internal marketing and affiliate marketing programs.

Breadcrumb Navigation

Navigational technique used to help search engines and website users understand the relationship between pages.
Example breadcrumb navigation:

Your SEO Plan » Getting Indexed » Sitemaps

Whatever page the user is on is unlinked, but the pages above it within the site structure are linked to, and organized starting with the home page, right on down through the site structure.

Broken Link

A hyperlink which is not functioning. A link which does not lead to the desired location.
Links may broken for a number of reason, but four of the most common reasons are

a website going offline
linking to content which is temporary in nature (due to licensing structures or other reasons)
moving a page's location
changing a domain's content management system
Most large websites have some broken links, but if too many of a site's links are broken it may be an indication of outdated content, and it may provide website users with a poor user experience. Both of which may cause search engines to rank a page as being less relevant.

Xenu Link Sleuth is a free software program which crawls websites to find broken links.

Browser

Client used to view the world wide web.
The most popular browsers are Microsoft's Internet Explorer, Mozilla's Firefox, Safari, and Opera.

Buying Cycle

Before making large purchases consumers typically research what brands and products fit their needs and wants. Keyword based search marketing allows you to reach consumers at any point in the buying cycle. In many markets branded keywords tend to have high search volumes and high conversion rates.
The buying cycle may consist of the following stages

Problem Discovery: prospect discovers a need or want.
Search: after discovering a problem look for ways to solve the need or want. These searches may contain words which revolve around the core problem the prospect is trying to solve or words associated with their identity.
Evaluate: may do comparison searches to compare different models, and also search for negative information like product sucks, etc.
Decide: look for information which reinforces your view of product or service you decided upon
Purchase: may search for shipping related information or other price related searches. purchases may also occur offline
Reevaluate: some people leave feedback on their purchases . If a person is enthusiastic about your brand they may cut your marketing costs by providing free highly trusted word of mouth marketing.
See also:

Waiting for Your Cat to Bark? - book by Brian & Jeffrey Eisenberg about the buying cycle and Persuading Customers When They Ignore Marketing.

C

Cache

Copy of a web page stored (indexed) by a search engine. When you search the web you are not actively searching the whole web, but are searching files in the search engine index.
Some search engines provide links to cached versions of pages in their search results, and allow you to strip some of the formatting from cached copies of pages.

Calacanis, Jason
Founder of Weblogs, Inc. Also pushed AOL to turn Netscape into a Digg clone.
See also:

Calacanis.com - Jason's blog

Canonical URL

Many content management systems are configured with errors which cause duplicate or exceptionally similar content to get indexed under multiple URLs. Many webmasters use inconsistent link structures throughout their site that cause the exact same content to get indexed under multiple URLs. The canonical version of any URL is the single most authoritative version indexed by major search engines. Search engines typically use PageRank or a similar measure to determine which version of a URL is the canonical URL.
Webmasters should use consistent linking structures throughout their sites to ensure that they funnel the maximum amount of PageRank at the URLs they want indexed. When linking to the root level of a site or a folder index it is best to end the link location at a / instead of placing the index.html or default.asp filename in the URL.

Examples of URLs which may contain the same information in spite of being at different web addresses:

http://www.seobook.com/
http://www.seobook.com/index.shtml
http://seobook.com/
http://seobook.com/index.shtml
http://www.seobook.com/?tracking-code
Catalog (see Index)

Catch All Listing

A listing used by pay per click search engines to monetize long tail terms that are not yet targeted by marketers. This technique may be valuable if you have very competitive key words, but is not ideal since most major search engines have editorial guidelines that prevent bulk untargeted advertising, and most of the places that allow catch all listings have low traffic quality. Catch all listings may be an attractive idea on theme specific search engines and directories though, as they are already pre qualified clicks.

CGI

Common Gateway Interface - interface software between a web server and other machines or software running on that server. Many cgi programs are used to add interactivity to a web site.
Client
A program, computer, or process which makes information requests to another computer, process, or program.

Cloaking

Displaying different content to search engines and searchers. Depending on the intent of the display discrepancy and the strength of the brand of the person / company cloaking it may be considered reasonable or it may get a site banned from a search engine.
Cloaking has many legitimate uses which are within search guidelines. For example, changing user experience based on location is common on many popular websites.

See also:

The Definitive Guide to Cloaking - Dan Kramer's guide to cloaking. I also interviewed Dan here.
KloakIt - cheaply priced cloaking software
Fantomaster - more expensive cloaking software
Cluetrain Manifesto, The
Book about how the web is a marketplace, and how it is different from traditional offline business.
See also:

The Cluetrain Manifesto website - offers the book for free online.

Clustering

In search results the listings from any individual site are typically limited to a certain number and grouped together to make the search results appear neat and organized and to ensure diversity amongst the top ranked results. Clustering can also refer to a technique which allows search engines to group hubs and authorities on a specific topic together to further enhance their value by showing their relationships.
See also

Google Touchgraph - interesting web application that shows the relationship between sites Google returns as being related to a site you enter.

CMS (Content Management System)

This is a tool used to make it easier to update and add information to a website.
An example of a CMS system might be a blog management system or a product database which updates products on your site. When configured by a highly profesional SEO company, CMS systems and database system can be extremely useful to in terms of SEO, some can auto generate sitemaps and google sitemaps. Others may hinder SEO with bad links and duplicate content.

Co-citation

In topical authority based search algorithms links which appear near one another on a page may be deemed to be related to one another. In algorithms like latent semantic indexing words which appear near one another often are frequently deemed to be related.
Comments
Many blogs and other content management systems allow readers to leave user feedback.
Leaving enlightening and thoughtful comments on someone else's related website is one way to help get them to notice you.

See also:

blog comment spam - the addition of low value or no value comments to other's websites

Comments Tag

Some web developers also place comments in the source code of their work to help make it easy for people to understand the code.
HTML comments in the source code of a document appear as <!-- your comment here -->. They can be viewed if someone types views the source code of a document, but do not appear in the regular formatted HTML rendered version of a document.

In the past some SEOs would stuff keywords in comment tags to help increase the page keyword density, but search has evolved beyond that stage, and at this point using comments to stuff keywords into a page adds to your risk profile and presents little ranking upside potential.

Compacted Information

Information which is generally and widely associated with a product. For example, most published books have an ISBN.
As the number of product databases online increases and duplicate content filters are forced to get more aggressive the keys to getting your information indexed are to have a site with enough authority to be considered the most important document on that topic, or to have enough non compacted information (for example, user reviews) on your product level pages to make them be seen as unique documents.

Conceptual Links

Links which search engines attempt to understand beyond just the words in them. Some rather advanced search engines are attempting to find out the concept links versus just matching the words of the text to that specific word set. Some search algorithms may even look at co-citation and words near the link instead of just focusing on anchor text.
Concept Search
A search which attempts to conceptually match results with the query, not necessarily with those words, rather their concept.
For example, if a search engine understands a phrase to be related to another word or phrase it may return results relevant to that other word or phrase even if the words you searched for are not directly associated with a result. In addition, some search engines will place various types of vertical search results at the top of the search results based on implied query related intent or prior search patterns by you or other searchers.

Contextual Advertising
Advertising programs which generate relevant advertisements based on the content of a webpage.
See also:

Google AdSense is the most popular contextual advertising program.
Conversion
Many forms of online advertising are easy to track. A conversion is reached when a desired goal is completed.
Most offline ads have generally been much harder to track than online ads. Some marketers use custom phone numbers or coupon codes to tie offline activity to online marketing.

Here are a few common example desired goals

a product sale
completing a lead form
a phone call
capturing an email
filling out a survey
getting a person to pay attention to you
getting feedback
having a site visitor share your website with a friend
having a site visitor link at your site
Bid management, affiliate tracking, and analytics programs make it easy to track conversion sources.

See also:

Google Conversion University - free conversion tracking information
Google Website Optimizer - free multi variable testing product offered by Google.
Copyright
The legal rights to publish and reproduce a particular piece of work.
See also:

Copyright.gov

Cookie

Small data file written to a user's local machine to track them. Cookies are used to help websites customize your user experience and help affiliate program managers track conversions.
CPA
Cost per action. The effectiveness of many other forms of online advertising have their effectiveness measured on a cost per action basis. Many affiliate marketing programs and contextual ads are structured on a cost per action basis. An action may be anything from an ad click, to filling out a lead form, to buying a product.
CPC
Cost per click. Many search ads and contextually targeted ads are sold in auctions where the advertiser is charged a certain price per click.
See also:

Google AdWords - Google's pay per click ad program which allows you to buy search and contextual ads.
Google AdSense - Google's contextual ad program.
Microsoft AdCenter - Microsoft's pay per click ad platform.
Yahoo! Search Marketing - Yahoo!'s pay per click ad platform
CPM
Cost per thousand ad impressions.
Many people use CPM as a measure of how profitable a website is or has the potential of becoming.

Crawl Depth

How deeply a website is crawled and indexed.
Since searches which are longer in nature tend to be more targeted in nature it is important to try to get most or all of a site indexed such that the deeper pages have the ability to rank for relevant long tail keywords. A large site needs adequate link equity to get deeply indexed. Another thing which may prevent a site from being fully indexed is duplicate content issues.

Crawl Frequency

How frequently a website is crawled.
Sites which are well trusted or frequently updated may be crawled more frequently than sites with low trust scores and limited link authority. Sites with highly artificial link authority scores (ie: mostly low quality spammy links) or sites which are heavy in duplicate content or near duplicate content (such as affiliate feed sites) may be crawled less frequently than sites with unique content which are well integrated into the web.

See also:

Google's Matt Cutts video on Google Crawling Patterns
Matt Cutts post Indexing Timeline - mentions sites with unnatural link profiles may not be crawled as frequently or deeply
CSS
Cascading Style Sheets is a method for adding styles to web documents.
Note: Using external CSS files makes it easy to change the design of many pages by editing a single file. You can link to an external CSS file using code similar to the following in the head of your HTML documents

<link rel="stylesheet" href="http://www.seobook.com/style.css" type="text/css" />

See also

W3C: CSS - official guidelines for CSS
CSS Zen Garden - examples of various CSS layouts
Glish.com - examples of various CSS layouts, links to other CSS resources
CTR
Clickthrough rate - the percentage of people who view click on an advertisement they viewed, which is a way to measure how relevant a traffic source or keyword is. Search ads typically have a higher clickthrough rate than traditional banner ads due to being highly relevant to implied searcher demand.
Cutts, Matt
Google's head of search quality.
See also:

Matt Cutts blog
Interview of Matt Cutts
SEO Videos by Matt Cutts
Cybersquatting
Registering domains related to other trademarks or brands in an attempt to cash in on the value created by said trademark or brand.

D

Dayparting

Turning ad campaigns on or off, changing ad bid price, or budget constraints based on bidding more when your target audience is available and less when they are less likely to be available.
Dead Link
A link which is no longer functional.
Most large high quality websites have at least a few dead links in them, but the ratio of good links to dead links can be seen as a sign of information quality.

Deep Link

A link which points to an internal page within a website.
When links grow naturally typically most high quality websites have many links pointing at interior pages. When you request links from other websites it makes sense to request a link from their most targeted relevant page to your most targeted relevant page. Some webmasters even create content based on easy linking opportunities they think up.

Dedicated Server

Server which is limited to serving one website or a small collection of websites owned by a single person or business. Low quality websites sharing a server or IP address can bring down the trust associated with the other websites on that server.

Deep Link Ratio

The ratio of links pointing to internal pages to overall links pointing at a website.
A high deep link ratio is typically a sign of a legitimate natural link profile.

De-Listing

Temporarily or permanently becoming de-indexed from a directory or search engine.
De-indexing may be due to any of the following:

Pages on new websites (or sites with limited link authority relative to their size) may be temporarily de-indexed until the search engine does a deep spidering and re-cache of the web.
During some updates search engines readjust crawl priorities.
You need a significant number of high quality links to get a large website well indexed and keep it well indexed.
Duplicate content filters, inbound and outbound link quality, or other information quality related issues may also relate to re-adjusted crawl priorities.
Pages which have changed location and are not properly redirected, or pages which are down when a search engine tries to crawl them may be temporarily de-indexed.
Search Spam:
If a website tripped an automatic spam filter it may return to the search index anywhere from a few days to a few months after the problem has been fixed.
If a website is editorially removed by a human you may need to contact the search engine directly to request reinclusion.

Del.icio.us

Social bookmarking website.

Demographics

Statistical data or characteristics which define segments of a population.
Some internet marketing platforms, such as AdCenter and AdWords, allow you to target ads at websites or searchers who fit amongst a specific demographic. Some common demographic data points are gender, age, income, education, location, etc.

Denton, Nick

Publisher of Gawker, a popular ring of topical weblogs, which are typically focused on controversy.
See also:

Nick Denton.org - official blog, where Nick often talks about business and his various blogs.
Description
Directories and search engines provide a short description near each listing which aims to add context to the title.
High quality directories typically prefer the description describes what the site is about rather than something that is overtly promotional in nature. Search engines typically

use a description from a trusted directory (such as DMOZ or the Yahoo! Directory) for homepages of sites listed in those directories
use the page meta description (especially if it is relevant to the search query and has the words from the search query in it)
attempt to extract a description from the page content which is relevant for the particular search query and ranking page (this is called a snippet)
or some combination of the above
Digg
Social news site where users vote on which stories get the most exposure and become the most popular.
See also:

Digg.com

Directory
A categorized catalog of websites, typically manually organized by topical editorial experts.
Some directories cater to specific niche topics, while others are more comprehensive in nature. Major search engines likely place significant weight on links from DMOZ and the Yahoo! Directory. Smaller and less established general directories likely pull less weight. If a directory does not exercise editorial control over listings search engines will not be likely to trust their links at all.

DMOZ

The Open Directory Project is the largest human edited directory of websites. DMOZ is owned by AOL, and is primarily ran by volunteer editors.

DNS

Domain Name Server or Domain Name System. A naming scheme mechanism used to help resolve a domain name / host name to a specific TCP/IP Address.
Domain
Scheme used for logical or location organization of the web. Many people also use the word domain to refer to a specific website.

Doorway Pages

Pages designed to rank for highly targeted search queries, typically designed to redirect searchers to a page with other advertisements.
Some webmasters cloak thousands of doorway pages on trusted domains, and rake in a boatload of cash until they are caught and de-listed. If the page would have a unique purpose outside of search then search engines are generally fine with it, but if the page only exists because search engines exist then search engines are more likely to frown on the behavior.

Dreamweaver

Popular web development and editing software offering a what you see is what you get interface.
See also:

Duplicate Content (+ Mirroring)

Content which is duplicate or near duplicate in nature.
Search engines do not want to index multiple versions of similar content. For example, printer friendly pages may be search engine unfriendly duplicates. Also, many automated content generation techniques rely on recycling content, so some search engines are somewhat strict in filtering out content they deem to be similar or nearly duplicate in nature.

See also:

Duplicate Content Detection - video where Matt Cutts talks about the process of duplicate content detection
Identifying and filtering near-duplicate documents
Search Engine Patents On Duplicated Content and Re-Ranking Methods
Stuntdubl: How to Remedy Duplicate Content

Dynamic Content

Content which changes over time or uses a dynamic language such as PHP to help render the page.
In the past search engines were less aggressive at indexing dynamic content than they currently are. While they have greatly improved their ability to index dynamic content it is still preferable to use URL rewriting to help make dynamic content look static in nature.

Dynamic Languages

Programming languages such as PHP or ASP which build web pages on the fly upon request.

E

Earnings Per Click

Many contextual advertising publishers estimate their potential earnings based on how much they make from each click.
Editorial Link
Search engines count links as votes of quality. They primarily want to count editorial links that were earned over links that were bought or bartered.
Many paid links, such as those from quality directories, still count as signs of votes as long as they are also associated with editorial quality standards. If they are from sites without editorial control, like link farms, they are not likely to help you rank well. Using an algorithm similar to TrustRank, some search engines may place more trust on well known sites with strong editorial guidelines.

Emphasis

An HTML tag used to emphasize text.
Please note that it is more important that copy reads well to humans than any boost you may think you will get by tweaking it for bots. If every occurrence of a keyword on a page is in emphasis that will make the page hard to read, convert poorly, and may look weird to search engines and users alike.

<em>emphasis</em> would appear as emphasis

Entry Page (or landing page)

The page which a user enters your site.
If you are buying pay per click ads it is important to send visitors to the most appropriate and targeted page associated with the keyword they searched for. If you are doing link building it is important to point links at your most appropriate page when possible such that

if anyone clicks the link they are sent to the most appropriate and relevant page
you help search engines understand what the pages on your site are associated with.

Ethical SEO

Search engines like to paint SEO services which manipulate their relevancy algorithms as being unethical. Any particular technique is generally not typically associated with ethics, but is either effective or ineffective.
Some search marketers lacking in creativity tend to describe services sold by others as being unethical while their own services are ethical. Any particular technique is generally not typically associated with ethics, but is either effective or ineffective.

The only ethics issues associated with SEO are generally business ethics related issues. Two of the bigger frauds are

• Not disclosing risks: Some SEOs may use high risk techniques when they are not needed. Some may make that situation even worse by not disclosing potential risks to clients.
  Taking money & doing nothing: Since selling SEO services has almost no start up costs many of the people selling services may not actually know how to competently provide them. Some shady people claim to be SEOs and bilk money out of unsuspecting small businesses.
  As long as the client is aware of potential risks there is nothing unethical about being aggressive.

Everflux

Major search indexes are constantly updating. Google refers to this continuous refresh as everflux.
In the past Google updated their index roughly once a month. Those updates were named Google Dances, but since Google shifted to a constantly updating index Google no longer does what was traditionally called a Google Dance.

See also:

Matt Cutts Google Terminology Video - Matt talks about the history of Google Updates and the shift from Google Dances to everflux.
Expert Document
Quality page which links to many non-affiliated topical resources.
See also:

Hilltop: A Search Engine based on Expert Documents

External Link

Link which references another domain.
Some people believe in link hoarding, but linking out to other related resources is a good way to help search engines understand what your site is about. If you link out to lots of low quality sites or primarily rely on low quality reciprocal links some search engines may not rank your site very well. Search engines are more likely to trust high quality editorial links (both to and from your site).

F

Fair Use

The stated exceptions of allowed usage of work under copyright without requiring permission of the original copyright holder. Fair use is covered in section 107 of the Copyright code.
See also:

US Copyright Office Section 107

Favicon

Favorites Icon is a small icon which appears next to URLs in a web browser.
Upload an image named favicon.ico in the root of your site to have your site associated with a favicon.

Feed

Many content management, systems such as blogs, allow readers to subscribe to content update notifications via RSS or XML feeds. Feeds can also refer to pay per click syndicated feeds, or merchant product feeds. Merchant product feeds have become less effective as a means of content generation due to improving duplicate content filters.
Feed Reader
Software or website used to subscribe to feed update notifications.
See also:

Bloglines - popular web based feed reader
Google Reader - popular web based feed reader
My Yahoo! - allows you to subscribe to feed updates
FeedDemon - desktop based feed reader

FFA

Free for all pages are pages which allow anyone to add a link to them. Generally these links do not pull much weight in search relevancy algorithms because many automated programs fill these pages with links pointing at low quality websites.
Filter
Certain activities or signatures which make a page or site appear unnatural might make search engines inclined to filter / remove them out of the search results.
For example, if a site publishes significant duplicate content it may get a reduced crawl priority and get filtered out of the search results. Some search engines also have filters based on link quality, link growth rate, and anchor text. Some pages are also penalized for spamming.

Firefox

An alternative browser to Microsoft's Internet Explorer. Free download from the Firefox website.

Flash

Vector graphics-based animation software which makes it easier to make websites look rich and interactive in nature.
Search engines tend to struggle indexing and ranking flash websites because flash typically contains so little relevant content. If you use flash ensure:

you embed flash files within HTML pages
you use a noembed element to describe what is in the flash
you publish your flash content in multiple separate files such that you can embed appropriate flash files in relevant pages
Forward Links (see Outbound Links)

Frames

A technique created by Netscape used to display multiple smaller pages on a single display. This web design technique allows for consistent site navigation, but makes it hard to deep link at relevant content.
Given the popularity of server side includes, content management systems, and dynamic languages there really is no legitimate reason to use frames to build a content site today.

Fresh Content

Content which is dynamic in nature and gives people a reason to keep paying attention to your website.
Many SEOs talk up fresh content, but fresh content does not generally mean re-editing old content. It more often refers to creating new content. The primary advantages to fresh content are:

Maintain and grow mindshare: If you keep giving people a reason to pay attention to you more and more people will pay attention to you, and link to your site.
Faster idea spreading: If many people pay attention to your site, when you come out with good ideas they will spread quickly.
Growing archives: If you are a content producer then owning more content means you have more chances to rank. If you keep building additional fresh content eventually that gives you a large catalog of relevant content.
Frequent crawling: Frequently updated websites are more likely to be crawled frequently.

FTP

File Transfer Protocol is a protocol for transferring data between computers.
Many content management systems (such as blogging platforms) include FTP capabilities. Web development software such as Dreamweaver also comes with FTP capabilities. There are also a number of free or cheap FTP programs such as Cute FTP, Core FTP, and Leech FTP.

Fuzzy Search

Search which will find matching terms when terms are misspelled (or fuzzy).

Fuzzy search technology is similar to stemming technology, with the exception that fuzzy search corrects the misspellings at the users end and stemming searches for other versions of the same core word within the index.

G

GAP

Google Advertising Professional is a program which qualifies marketers as being proficient AdWords marketers.

Google

The world's leading search engine in terms of reach. Google pioneered search by analyzing linkage data via PageRank. Google was created by Stanford students Larry Page and Sergey Brin.

Google Base

Free database of semantically structured information created by Google.
Google Base may also help Google better understand what types of information are commercial in nature, and how they should structure different vertical search products.

Google Bombing

Making a page rank well for a specific search query by pointing hundreds or thousands of links at it with the keywords in the anchor text.
See News Article: miserable failure

Google Bowling

Knocking a competitor out of the search results by pointing hundreds or thousands of low trust low quality links at their website.
Typically it is easier to bowl new sites out of the results. Older established sites are much harder to knock out of the search results.

Google Checkout

Payment service provided by Google which helps Google better understand merchant conversion rates and the value of different keywords and markets.

Google Dance

In the past Google updated their index roughly once a month. Those updates were named Google Dances, but since Google shifted to a constantly updating index, Google no longer does what was traditionally called a Google Dance.
Major search indexes are constantly updating. Google refers to this continuous refresh as everflux.

The second meaning of Google Dance is a yearly party at Google's corporate headquarters which Google holds for search engine marketers. This party coincides with the San Jose Search Engine Strategies conference.

Google Keyword Tool

Keyword research tool provided by Google which estimates the competition for a keyword, recommends related keywords, and will tell you what keywords Google thinks are relevant to your site or a page on your site.

Google Sitemaps

Program which webmasters can use to help Google index their contents.
Please note that the best way to submit your site to search engines and to keep it in their search indexes is to build high quality editorial links.

Google Supplemental Index

Index where pages with lower trust scores are stored. Pages may be placed in Google's Supplemental Index if they consist largely of duplicate content, if the URLs are excessively complex in nature, or the site which hosts them lacks significant trust.
Google Traffic Estimator
Tool which estimates bid prices and how many Google searchers will click on an ad for a particular keyword.
If you do not submit a bid price the tool will return an estimated bid price necessary to rank #1 for 85% of Google's queries for a particular keyword.

Google Trends

Tool which allows you to see how Google search volumes for a particular keyword change over time.

Google Website Optimizer

Free multi variable testing platform used to help AdWords advertisers improve their conversion rates.

Guestbook Spam

A type of low quality automated link which search engines do not want to place much trust on.

H

Headings

The heading element briefly describes the subject of the section it introduces.
Heading elements go from H1 to H6 with the lower numbered headings being most important. You should only use a single H1 element on each page, and may want to use multiple other heading elements to structure a document. An H1 element source would look like:

<h1>Your Topic</h1>

Heading elements may be styled using CSS. Many content management systems place the same content in the main page heading and the page title, although in many cases it may be preferential to mix them up if possible.

See also:

W3C: Headings
Headline
The title of an article or story.

Hidden Text

SEO technique used to show search engine spiders text that human visitors do not see.
While some sites may get away with it for a while, generally the risk to reward ratio is inadequate for most legitimate sites to consider using hidden text.

Hilltop

Algorithm which ranks results largely based on unaffiliated expert citations.
See also:

Hilltop: A Search Engine based on Expert Documents

Hijacking

Making a search engine believe that another website exists at your URL. Typically done using techniques such as a 302 redirect or meta refresh.
Home Page
The main page on your website, which is largely responsible for helping develop your brand and setting up the navigational schemes that will be used to help users and search engines navigate your website.
As far as SEO goes, a home page is typically going to be one of the easier pages to rank for some of your more competitive terms, largely because it is easy to build links at a home page. You should ensure your homepage stays focused and reinforces your brand though, and do not assume that most of your visitors will come to your site via the home page. If your site is well structured many pages on your site will likely be far more popular and rank better than your home page for relevant queries.

Hosting

HTTP

HyperText Transfer Protocol is the foremost used protocol to communicate between servers and web browsers. Hypertext transfer protocol is the means by which data is transferred from its residing location on a server to an active browser.
Hubs
Topical hubs are sites which link to well trusted within their topical community. A topical authority is a page which is referenced from many topical hub sites. A topical hub is a page which references many authorities.

See also:

Mike Grehan on Topic Distillation [PDF]
Jon Klienberg's Authoritative sources in a hyperlinked environment [PDF]
Jon Klienberg's home page