A copy of a web page that is stored by a search engine and used to index the page in search results. There are some search engines that provide links to cached versions of web pages for users to view in the search results.

The rate at which a search engine’s publicly displayed cache image of a Web document is changed. Used by some SEOs to measure the quality and value of Web documents and sites for search engine optimization .

The length of time that elapses from a page’s contents being reported in a search engine cache image until the page contents are found for specific queries.

Advertising intended to convince users to perform a particular action.

A US law regulating commercial email (e.g. email marketing). The acronym stands for Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003.

An abbreviation of "Completely Automated Public Turing test to tell Computers and Humans Apart". A CAPTCHA system contains a graphical representation of several letters and a field in which those letters must be entered. The intention is to prevent access to automated systems.

A website language that enables website designers to attach style (fonts, spacing and aural cues) to structure that include HTML and XML applications. Can be used in search engine optimization to remove design elements from a page's main file. As a result, the file is smaller, and the content aspect of the file makes up a larger percentage of the whole. Some believe that this will deliver higher rankings, but the evidence of this is suspect at best. Cascading Style Sheets can also be used to create invisible text, although this is likely to result in the Google Death Penalty. Often abbreviated as CSS.

A term that advertising and graphic design firms use to refer to landing pages.

The process by which a search engine regularly or occasionally changes listings in its results due to content or algorithmic factors. Churn is normal for most queries.

A program or robot used to click on paid links or listings within a search engine. This process artificially and fraudulently boosts click amounts.

Clicks on paid search advertising that are not made by actual searchers, but by others with an incentive to cost and advertiser money. Click fraud can come from competitors trying to drive up an advertisers media spend or from website owners attempting to drive up their Google AdSense revenue.

A program or application that makes information requests to other computers, processes, or programs. The client communicates through networks.

The highly risky search engine optimization technique of serving different content to website visitors and to search engine robots. The belief is that the text being served to the robots can be optimized for search engines, and the text served to actual visitors be optimized for website transactions. This is one of the more common causes of the Google Death Penalty.

Cloud Computing is an alternative method of storing data and programs that focuses on online storage. Originally, software, data, and other information that a user needed to access was stored on a computer’s hard drive. For example, your word documents are saved on your computer as is the Microsoft Word software program. The cloud is a metaphor for the internet as a location to store information, instead of the computer’s hard drive. The concept behind cloud computing is that documents and software, even operating systems can be stored online. Google Docs is a good example of cloud computing. With Google Docs, if a user wanted to edit a document, they would open it up from an online location and edit it without ever having to download anything. This means computers will need less memory space because the computer will function as a portal to the information in the internet “cloud” but won’t actually store it.

A HTML tag that is hidden from users (unless they look at a page's source code). In theory, search engines could read a page's comment tag and use it in its relevancy calculation, but it is not believed that any of the major search engines currently do so.