scalability : The ability to expand Web server resources as needed.

Scalable Inman Flash Replacement (sIFR) : A powerful technology that enables a Web designer to use a wide variety of fonts on their Web pages without sacrificing search-engine friendliness or accessibility.

scraper: A person who sends a robot to a Web site to copy (or “scrape”) the entire site and then republish it as their own.

search box : The text box in a search engine page where users type their search queries, or whatever it is that they’re looking for.

search engine: A Web application designed to hunt for specific keywords and group them according to relevance.

search query: The word or phrase that a user types into the search box of a search engine.

search verticals : Links to specialized vertical search engines that narrow a search into a specific type of result, such as images or news. Clicking one of these links takes a user to a results page with only images or only news.

segmentation test : Testing the variables in incoming Web traffic, such as finding out the demographics of the incoming traffic by asking them to answer certain questions.

SEO: An acronym for Search Engine Optimization.

SERP: An acronym for Search Engine Results Page.

server : The software and hardware that runs a Web site.

server logs : Records that measure the amount of traffic that a Web site receives. A server automatically creates a server log of all the activity it performs during a given time period, be it hours, days, or minutes.

session : The current time period a user is active on a Web site after logging on.

siloing : The process of organizing a Web site’s content into distinct subject categories, in order to group related content. Each silo has its own landing page and supporting pages.

site map : A Web page containing links to the pages in that Web site, similar to a table of contents.

site navigability: Link structure for moving around a Web site.

slip : A measure of how quickly visitors leave a Web page.

social media: Any sort of online environment that allows social interaction, including blogs, social news sites like Digg and Reddit, social networking sites like MySpace and Facebook, and others.

social networking site: A Web site where people can meet and interact with one another.

social news site : A site where news stories and articles from anywhere on the Web can be voted on by users, and the importance of a story or article is determined by the audience rather than by the editors of the site or source. Examples include Digg, StumbleUpon, and Reddit.

source code : The plain HTML code used to create a Web page.

spam : Any tactic or Web page that is used to deceive a search engine into a false understanding of what the whole Web site is about or its importance.

spider : A small program that search engines use to read and rank Web sites. Spiders are also referred to as robots, bots, or crawlers.

spider trap : A situation where a spider gets caught in an endless loop and is forced to abandon the Web page because it has no other alternative.

sponsored links : Search engine results that are paid for by advertisers. These paid results often appear above the organic results in a search engine page.

stemming : Using multiple forms of a word (such as “customize” instead of “customization”).

stickiness : A measure of how long a user stays on a Web page.

stop words : Very common words such as the, a, to, if, who, and so forth, which serve to connect ideas in search phrases but don't add much in the way of meaning to the phrases’ content. Stop words are ignored by search engines.

subdomain: A dependent domain set up within a primary domain. For example, in, events is the subdomain, .classiccarcustomization is the domain, and .com is the top-level domain.