This search engine glossary will help you better understand some of the terms commonly used in the SEO industry.

404 Error Page

The web page that displays when a user tries to view a page that no longer exists or the page file name has changed.

Adandonment Rates

Percentage of site visitors who view a page and then exit without linking to other pages on the site.

Alt tags

More correctly, these are ALT "attributes" (e.g. IMG is a "tag"). This is text coded in the HTML that associates words with web graphics.

Back Links

The number of links pointing to a website, "link popularity".

Cache

Web content saved by the search engines in their indexes.

Call-To-Action

A way to engage the website visitor that encourages them to interact with the company.

Cloaking

At the same URL (web address) showing one page to a search engine spider and a different page to a human visitor. Frowned upon by search engines as deceptive, sites may be severely penalized by the engines if they use cloaking.

Crawler-based search engines

Engines that use automated software to index the billions of files online.

Conversion

When a website visitor takes a desired action, such as a sale or downloads a file.

CTR "Click Through Rate"

Percentage of users who click an online ad after viewing it.

Directories

Websites that list other sites by category, e.g. Yahoo! Directory.

DMOZ

A directory run by volunteers under the Open Directory project, www.dmoz.org.

Flash

Macromedia software that creates vector-based graphic animations with small file sizes for use online.

Framed site

Using a specific type of HTML code that places "pages inside pages". Has significant disadvantages and a few advantages.

H1, H2 tags

In HTML, the code used to define a page title or subhead.

HTML Text

Text on a web page that is created using HTML (which can be indexed by the engines) as opposed to a graphic (which cannot).

Hyperlinks

A link from one web page to another (links can also point to another location on the same page).

Indexing / indexable

Online content that the search engines can index. Some content is not indexable (e.g. locked PDF files, text in a graphic).

JavaScript

A programming script used on websites.

Keyword Stemming

Google searches not only for your search terms, but also for words that are similar to some or all of those terms, including plurals.

Link Popularity

The number of links pointing to a website.

Meta Description

"Hidden" HTML code that contains a descriptive sentence or two about the web page.

Natural Listings

That part of the search engine results that is not paid for, typically in the central area of the results page.

Off-The-Page

Factors considered by the search engines when ranking a page that are not part of the web page, e.g. back links.

On-The-Page

Factors considered by the search engines when ranking a page that are part of the web page, e.g. text content, title text, etc.

Organic Listings

See "Natural Listings"

Page Rank

Devised by Google, it measures not only how many links point to a website, but the "quality" of the sites providing the links.

Page Views

The number of requests to view a specific web page in a specific time frame (the same person could make multiple requests).

Paid Inclusion

Paying money to be listed in a search engine or online directory.

Paid Placement

Paying money to have an advertisement shown on a search engine results page.

PDF

Portable Document Format created using Adobe Acrobat software.

Phrase Match

Performing a search with quotation marks around the phrase so that the search results will show web pages with the exact phrase.

Pop-up Ads

A form of online advertising that opens a new web browser window to display advertisements.

PPC "Pay Per Click"

Paying a small amount each time a user clicks on an online ad.

Redirect

A file on the server indicating that the requested page has permanently (301) or temporarily (302) been moved to another location.

Robots.txt

A text file that instructs the search engines about pages or directories to exclude from its database.

ROI "Return on Investment"

How much revenue is generated compared to how much was spent on a marketing campaign

Search Engine Marketing (SEM)

The practice of marketing and advertising through the search engines.

Search Engine Optimization (SEO)

Designing a website so that it ranks highly in the search engines when someone searches for specific phrases related to the site.

Search Engine Rankings

The position a site has on a search results page when a specific phrase is searched for.

Search Engine Referrals

Visitors who arrive at a website after clicking a link on a search engine results page.

Search Engine Results Page (SERP)

The page that displays in a search engine when a specific phrase is searched for.

Search Term

The word or words entered by the user into the search engine.

Similar Pages

Identifies sites that the search engines think are the same theme.

Title Tag

In HTML, an area where text is placed that shows at the very top of the browser window. Search engines consider this area critical.

Unique Visitors

The number of individuals who visit a website during a specific time (the same person visiting twice is only counted once).

Web Spider

Software that browses the Web in an automated manner and keeps a copy of visited pages in its database. Also known also as a crawler.

Webinar

Online seminar that may contain audio and video.

Search Engine Saturation

The number of web pages that a search engine has indexed from your website.