A set of rules that a search engine uses to rank the listings contained within its index, in response to a particular query. No search engine reveals exactly how its own algorithm works, to protect itself from competitors and those who wish to spam the search engine.
Backlinks
Doorway Page
A web page created expressly in hopes of ranking well for a term in a search engine's non-paid listings and which itself does not deliver much information to those viewing
it. Instead, visitors will often see only some enticement on the doorway page leading them to other pages (i.e., "Click Here To Enter), or they may be automatically propelled quickly past the doorway page. With cloaking, they may never see the doorway page at all. Several search engines have guidelines against doorway pages, though they are more commonly allowed in through paid inclusion programs. Also referred to as bridge pages, gateway pages and jump pages, are the other names.
Index
The collection of information a search engine has that searchers can query against. With crawler-based search engines, the index is typically copies of all the web pages they have found from crawling the web. With human-powered directories, the index contains the summaries of all web sites that have been categorized.
Landing Page
The specific web page that a visitor ultimately reaches after clicking a search engine listing. Marketers attempt to improve conversion rates by testing various landing page creative, which encompasses the entire user experience including navigation, layout and copy.
Link Popularity
A raw count of how "popular" a web page is based on the number of backlinks it has. It does not factor in link context or link quality, which are also important elements in how search engines make use of links to impact rankings.
Link Text
The text that is contained within a link. For example, search engine is a link that contains the link text "search engine."
Listings
The information that appears on a search engine's results page in response to a search.
Meta Search Engine
A search engine that gets listings from two or more other search engines, rather than through its own efforts.
Meta Tags
Information placed in a web page not intended for users to see but instead which typically passes information to search engine crawlers, browser software and some other applications.
Meta Description Tag
Allows page authors to say how they would like their pages described when listed by search engines. Not all search engines use the Meta description tag.
Meta Keywords Tag
Allows page authors to add text to a page to help with the search engine ranking process. Not all search engines use the Meta Keyword tag.
Meta Robots Tag
Allows page authors to keep their web pages from being indexed by search engines, especially helpful for those who cannot create robots.txt files. The Robots Exclusion page provides official details.
Organic Listings
Listings that search engines do not sell (unlike paid listings). Instead, sites appear solely because a search engine has deemed it editorially important for them to be included, regardless of payment. Paid inclusion content is also often considered "organic" even though it is paid for. This is because that content usually appears intermixed with unpaid organic results.
Outbound Links
Links on a particular web page leading to other web pages, whether they are within the same web site or other web sites.
Paid Inclusion
Advertising program where pages are guaranteed to be included in a search engine's index in exchange for payment, though no guarantee of ranking well is typically given. Marketers pay to be included in the directory, on a CPC basis or per-URL fee basis, with no guarantee of specific placement.
