SEO Glossary

Glossary of Search Engine Optimization (SEO) Terms

Algorithm – A complex mathematical formula used by a search engine to rank the web pages that it finds by crawling the web.

ALT Tags - Used to display a short text description of an image when you hover your mouse over it. The ALT description is also displayed in place of the image if the user is browsing with image display turned off.

Image ALT tags are useful to your page’s visitors. Equally as important, they can help with your search engine rankings by increasing the keyword density (if you use your keywords in your ALT tags).

   <img src="blue-widget.jpg" width=”156″ height=”175″
    ALT="Photo of blue widget">

Apache Web Server – The web server software that is most used on the internet today. 

Bad Neighborhood – A web page that has been penalized by a search engine (most notably Google) for using shady SEO tactics, such as hidden text or link farms.

Backlinks – Links from another web page to your web page. Most search engines provide an easy way to get a list of all of the backlinks to a specific page. Also referred to as Incoming Links

Broken Link – A link that no longer takes the user to the destination page when it is clicked on. This is usually the result of the destination page having been renamed or deleted from the server. Also referred to as a Dead Link.

Click-Through – The action of clicking on a link to visit a web page.

Click-Through-Rate (CTR) – The number of times a link is clicked on divided by the number of times that same link is displayed (called an impression).

   A link is displayed 100 times (100 impressions) and clicked
   on 5 times. The CTR is 5% (5/100=.05).

Cloaking – Serving one version of a page to a human visitor and a different version of the same page to the search engines. This is usually done to "fool" the search engines into giving the page a higher rank than it would normally receive while making sure the human visitor sees a useful and attractive page.

Note: Cloaking is discouraged by most major search engines, including Google.

Comment Tags – Used in a web page’s HTML source code to indicate certain information about a section of the page code. Some search engines will consider keywords contained in comment tags for keyword density purposes, others (including Google) will not.

    <!–This is a comment–>

Content – The information located on a web page. This includes text, images, and any other types of information that a webmaster places on the page.

Counter – A script that counts the number of hits, unique visitors, and/or page views that a web page (or an entire site) receives. These "stats" provide very useful information for the webmaster.

Crawler – A program used by search engines to "crawl" the web by following links from page to page. This is how most search engines "find" the web pages that they place in their index. Also referred to as a spider or robot.

Crawling The Web – Search engines use crawlers to move from web page to web page by following the links on the pages. The pages "found" are then ranked using an algorithm and indexed into the search engine database.

Cross Linking – This is where the owner of two or more websites interlink the sites in order to boost their search engine rankings. If detected, cross linking often results in a search engine penalty.

Dead Link – See Broken Link.

Deep Linking – Linking to a page that is one or more levels removed from the home directory. Deep linking is often desirable to build PageRank to a specific page on a website.


Description – A short sentence or paragraph that describes a web page’s content, usually used as part of a link to describe the page being linked to. See also link anchor text.

Description Meta Tag – A meta tag that describes the content of the web page in which it is found. Used by some search engines for keyword density purposes. Also, some SE’s will use the description meta tag for the description provided to a user when the page is returned in a listing of search results. It is recommended that you use a couple of your targeted keywords in the description meta tag.

     <META NAME=”Description” CONTENT=”This sentence
      describes the content on this page.”>

Directory – A categorized list of websites that is maintained by human editors instead of crawlers. is the most widely recognized directory on the web, but there are literally thousands of others.

Domain – The human-friendly "address, or URL" of a website. When a user types a URL into a web browser, a dedicated computer somewhere on the web known as a Domain Name Server, or DNS translates the URL into a discrete IP address which is then used to find the actual website being requested.

In the URL, is the domain.

Domain Name Servers (DNS) – These are special computers that translate human-friendly URLs into computer-friendly IP addresses. This process takes place every time a user requests a page from a website.

DNS Propagation – Every time a new domain name is registered (or an existing one is transferred to a new DNS), the information about the domain and the DNS that hosts it must make its way around the entire internet. This process usually takes around 24 hours, during which time the domain will be inaccessible to users.

Doorway Page – A page that is usually optimized for a particular search engine and search term. Multiple doorway pages are often used to help ensure that the same basic content is ranked well on several different search engines. The use of doorway pages for this purpose is frowned upon by most larger search engines, including Google.

Duplicate Content – Two or more separate web pages that contain substantially the same content are said to contain duplicate content.

Google and other top search engines have set up filters to detect duplicate content when their crawlers are active on the web. When pages containing duplicate content are detected, they are often assessed a duplicate content penalty which means a lowering of the page’s ranking from what it would have received naturally.

Dynamic Content (dynamic pages) – Web pages that are often generated from database information based upon queries initiated by users. Dynamic pages often include the ? character in the URL.

The URLs of dynamic pages often use these extensions: .asp, .cgm, or .cgi. Most search engines don’t index dynamic content very well (or at all). Google has recently been doing a better job at indexing them however.

Dynamic IP Address – An IP address that changes every time a computer logs on to the internet. See also Static IP Address.

Filters – A filter is a software routine that examines web pages during a robot’s crawl looking for search engine spam. If the filter detects the use of spam on the page, a ranking penalty is assessed.

Common filters look for hidden text, links to bad neighborhoods, and many other SEO techniques that the search engine doesn’t like. – The leading search engine on the internet today with approximately 80% of all search traffic. When people speak of search engine optimization (SEO), they’re often referring specifically to Google.

Googlebot – The crawler that Google uses on a daily basis to find and index new web pages.

Google Toolbar – A downloadable toolbar for Internet Explorer that allows a user to do a Google search without visiting the Google website. The toolbar also displays the Google PageRank (PR) of the page currently displayed in the browser. The latest version also includes a very good popup-blocker. The Google Toolbar is a must have for every serious webmaster.

The Google Toolbar can be downloaded here:

Header Tags – HTML tags that help outline a web page or draw attention to important information. Keywords located inside header tags can provide a rankings boost in the search engines.

     <h1>This is an H1 tag.</h1>
     <h2>This is an H2 tag.</h2>

Hidden Text and Hidden Links – Using a text font that is the same (or nearly the same) color as the background color, rendering the text or link invisible or very difficult to read. The same effect can also be achieved by using various HTML tricks.

Hidden text and hidden links are often used to artificially increase a web page’s keyword density for a keyword or keyphrase and/or to artificially boost the link popularity of other pages on your site(s).

The use of hidden text and hidden links is frowned upon by Google and most other search engines. Using them will most likely result in your web page(s) incurring a penalty by the search engines.

Hits – The term hits is commonly misused. Many people think of a hit as a visit to one of their web pages. This is incorrect. A hit takes place every time a file is accessed on your website.

For example, let’s say your friend’s home page has a logo gif and 12 pictures on it. Every time a visitor loads that page, 14 hits are recorded: 1 for the logo gif, 12 for the pictures, and one for the page itself. So don’t be all that impressed if he boasts that his site receives 1000 hits a day. In our example, those 1000 hits could have been generated by as few as 72 visitors to the site.

The only meaningful way to evaluate the traffic flow of a site is to consider the average daily or monthly number of unique visitors and page views a site receives.

Home Directory – The main directory where your site’s main index page is located. The index page in your home directory can be accessed like this:

Image Map – Placing separate hyperlinks on different areas of the same image. Clicking on different parts of the image will take the user to different web pages. Not very search engine friendly.

Inbound Links – See Backlinks.

Index – The list of web pages stored and ranked by a search engine. Also known as a database.

Indexing – After a search engine has crawled the web, it ranks the URLs found using various criteria (see algorithm) and places them in the database, or index.

IP Address – A unique numerical Internet Protocol Address (IP Address) that is assigned to every computer that connects to the internet. IP addresses can be either static (never unchanging) or dynamic (changes with every internet connection).

Your computer’s IP address is what enables it to be "found" on the internet in order to receive email, web pages, etc.


IP Spoofing – Returning an IP address that is different from the one that is actually assigned to the destination website. This is often done with redirects. A huge no-no (it’s even a criminal offense when done under certain circumstances).

Keyword (Key Phrase) – A word or phrase typed into a search engine in order to find web pages that contain that word or phrase. A web page can (and should be) optimized for specific keywords/phrases that are relevant to the content on that page.

Keywords Meta Tag – An HTML meta tag that lists all of the main keywords and key phrases that are contained on that web page. Some search engines use the keyword meta tag to help rank web pages in their databases. Google does not.

     <META NAME=”KEYWORDS” CONTENT=”small business,

Link Anchor Text – The "clickable" part of the link structure. Using keywords in the link anchor text of your inbound links will help your search engine rankings for those keywords.

     <a href=””>This is the link
      anchor text for this link</a>

Link Exchange – Placing a link to another website on your own site in exchange for a return link back. Also known as reciprocal linking.

Link Farm – A web page created solely for search engine ranking purposes that consists almost entirely of a long list of unrelated links. These types of pages are penalized by almost all search engines, including Google.

Link Popularity – A measure of how "popular" a web page is on the internet as measured by the number of inbound links pointing to your web page. Link popularity is one of the main factors used to help determine search engine rankings.

Linking – Placing a link to another web page (usually on another web site) on one of your own web pages.

Links – URLs placed within a web page so that when they’re clicked on the browser is served with a different web page, often on a completely different web site.

Log Files – Files that are constantly and automatically created and updated on your web server that provide very specific details about the activities taking place on your web site.

This includes referring URLs, IP addresses, pages visited, errors generated, number of unique visitors, total page views, total hits, and much more. Carefully reviewing your log files can provide valuable information about your site’s performance and visitors.

Meta Search Engine – A website that takes your search query and passes it on to several different search engines and directories, then summarizes the results in a logical manner for you to review.

Mirror Sites – Identical, but separate websites on different domains. They are commonly used legitimately by large websites to share heavy server loads, and by search engine spammers to generate more search engine referrals and revenue.

In general, the search engines frown upon mirror sites and do not hesitate to assess duplicate content penalties when they feel they are warranted.

Outbound Links – Links from your web page to another web page.

PageRank (PR) – A proprietary numerical score that is assigned by Google to every web page in their index. PR for each page is calculated by Google using a special mathematical algorithm, based on the number and quality (as determined by Google) of the inbound links to the page.

Page Views – Each time a web page on a site is accessed by a visitor, it counts as one page view. It doesn’t matter if the same user viewed the same page 5 minutes ago, it still represents another page view.

For example, let’s say that a website receives two unique visitors in one day. The first visitor surfs around the site and views a total of six pages. The second visitor views 11 pages. This represents 17 page views for the day by two unique visitors. (This poor webmaster needs to do some serious SEO and site promotion!)

Paid Inclusion – Some directories will only consider placing your URL into their database if you pay them a fee.

Yahoo charges a $299 per year evaluation fee for commercial sites. Note that this fee doesn’t guarantee that your URL will be accepted and placed in the Yahoo database, but rather that Yahoo will consider your site for inclusion in a timely manner. If your site is rejected, you’re just out your $299. But you do have an opportunity to appeal the decision.

Other smaller directories will guarantee to list your site upon payment of their fee, provided that your site meets their guidelines (these are clearly explained ahead of time).

Many search engines also have a paid inclusion program, including Inktomi and Alta Vista. You don’t have to pay to be included in search engines however. If you have a few quality inbound links to your site, the search engines will find and index your site on their own eventually.

The advantage of utilizing their paid inclusion services is they’ll usually crawl and index your site within 48 hours or less instead of the weeks or even months that it often takes otherwise.

Pay-Per-Click (PPC) Search Engines – This is a traffic generating method where a search engine or directory places your link in their searchable database and charges you a fee every time your URL comes up in a search and it gets clicked on. The amount of the fee that you pay is usually determined by bidding on keywords or keyphrases.

The two largest PPC search engines are Overture and Google AdWords. There are also numerous smaller PPC engines on the net, some very good a delivering affordable targeted traffic, others not.

Penalty – A punishment levied against a web page by a search engine as a result of using an SEO tactic that it doesn’t approve of. Tactics that most often result in penalties include using hidden text, sneaky redirects, and linking to a bad neighborhood.

A penalty usually results in a web page being credited for a lower Google PageRank (PR) than it has actually "earned". Penalties also result in a page being "buried" deep within the SERPS where it will almost never be found again by searchers.

Rankings – The order in which individual web pages are returned in the SERPS for a given search query. Search engines rank the web pages based upon relevancy to your search terms according to their proprietary algorithm.

Reciprocal Links – Links to another website placed on your site in exchange for links back to your site from theirs. This is a proven way to build link popularity which is instrumental in getting high search engine rankings.

Redirect – A tactic sometimes used to send a user to a different page that the one she found in the SERPS. For example, a webmaster optimizes a web page for a very popular keyword. When a user finds the page by searching on that keyword, she is subsequently redirected to a different, possibly non-relevant page that the webmaster stands ready to make money from.

This is considered to be an invalid use of a redirect and the search engines (including Google) will penalize pages that use one in this manner.

Referrer or Referring URL – The URL of the web page where a visitor clicked a link to come to your site.

Relevancy – The degree to which the content on a web page that is returned in a list of search results (SERPS) "matches" the topic of the information that the user was searching for. In other words, if you use the search phrase "small green widgets" and a page is returned that deals with "large red thingamajigs", the relevancy of that page is very poor.

Robot – A program used by a search engine to crawl the web in order to find, rank, and index new web pages.

Robots.txt – A special file that is commonly used to exclude some or all robots from crawling certain files or directories on a website. This file should b placed in your website’s root directory.

Search Engine Friendly – A web page that has been designed and optimized for high search engine rankings. A search engine friendly page also makes it easy for search engines to follow the links on the page.

Search Engine Optimization (SEO) – The process of optimizing a web page for high search engine rankings for a particular search term or set of search terms.

Search Engine Results Pages (SERPS) – The ranked listing of web pages that are returned for a specific search query.

Search Query – The keyword, keyphrase, or list of words that you type into a search engine to find web pages on a topic that you’re interested in. 

Search Term – A list of keywords or a keyphrase that a user types into a search engine to find a list of web pages related to topic that he/she is interested in.

SEO –  See Search Engine Optimization.

Server – A computer that hosts web pages and delivers them to a user’s internet browser when requested.  A dedicated server hosts one website only. A shared server hosts multiple websites. Dedicated servers deliver web pages faster and provide more capacity and features than shared servers, but they’re also considerably more expensive to use.

PageRank (PR) For Money – Selling or buying a link from a web page with a high Google PageRank for the stated purpose of increasing the other page’s PR. This is highly frowned upon by Google and will result in a penalty for both pages if Google finds out about it.

SERPS – See Search Engine Results Pages

Spam – When speaking of search engines, spam is loosely defined as any technique used to give your web page(s) an unfair ranking advantage over other pages.

Spider – See Crawler.

Static IP Address – An IP address that is permanently assigned to a computer. The IP address doesn’t change with each connection to the internet. See also Dynamic IP Address.

Submitting Your URLs – This is the process of telling a search engine or directory about your web pages. The URLs that you submit are placed into a queue for later crawling or human review.

If you have backlinks pointing to your web pages, there is usually no need to submit your URLs to the search engines because their crawlers will find the pages on their own and index them. You do need to submit your URLs to directories however because they use humans instead of robots to visit the sites that you submit and evaluate them.

Title Meta Tag – This HTML tag is used to provide web browsers and search engines with an "official" title for the page currently being displayed. Using a couple of keywords in your title tag can help boost the page’s search engine ranking for those keywords.

    <META NAME=”TITLE” CONTENT=”Page title goes here”>

Top-10 Ranking – A web page that is listed in the first 10 search results for a search query. Top-10 in Google also means on the first page using the standard search criteria

Traffic – A website’s average rate of traffic flow within a given time period. It can be measured in a couple ways, including unique visitors and total page views. Don’t confuse hits with unique visitors and page views. The term hits is virtually useless when evaluating website traffic statistics.

Unique Visitors – The number of visitors who access a website within a given time period (usually 24 hours) from a single IP address. If you visit the same website three times within a 24 hour period, your visits only count as one unique visit for that day.

URL (Uniform Resource Locator) – Each web page has it’s own specific human-friendly URL, or web address. URLs are mapped to computer-friendly IP addresses by special computers called Domain Name Servers, or DNSs.


User – See Visitor.

Visitor – A person who visits your website. Also known as a User.