The keywords tag, invisible part of your webpage) is used by a meta capable search engines to help aid in indexing your web site. Search engines use this information to determine under what relevant queries your web site will come up under. Since most searches are now done by combining word phrases,75% by recent studies.
Search engines may use metadata when indexing and classify website content. Standard meta-information includes:
file type
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
description
<meta name="description" content="Description of the page content" />
keywords
<meta name="keywords" content="Synonyms and phrases that classify page content" />
Keyword search is a search for documents containing one or more words specified by a user in a search engine text box.
A meta tag that allows the author to emphasize the importance of strategic words and phrases used within a Web page. Some search engines respond to this information, others ignore it. Don't use quotes around keywords or key phrases.
Meta Search Engine: A server that passes queries on to many search engines and directories, then summarizes the results. Ask Jeeves, Dogpile, Metacrawler, Metafind and Metasearch are meta search engines.
Meta tags: Information placed in the HTML header of a Web page, providing information that is not visible to browsers. The most common meta tags relevant to search engines are keyword and description tags.
Keyphrase search for documents containing an exact sentence or phrase specified by a user in a search engine text box.
A search engine is a searchable online database of internet resources. It has several components: search engine software, spider software, an index (database), and a relevancy algorithm (rules for ranking). The search engine software consists of a server or a collection of servers dedicated to indexing Internet Web pages, storing the results and returning lists of pages to match user queries. The spidering software constantly crawls the Web collecting Web page data for the index. The index is a database for storing the data. The relevancy algorithm determines how to rank queries. Examples of major search engines are Google, AOL, MSN and Lycos, etc.. Examples of major directories are Yahoo!, LookSmart and ODP.
Search strings or terms are the words entered by users into a search engine or directory to locate needed information.
Search Term is a single word or group of words used in a search engine document query. It also refers to the strategic keywords used to optimize Web page content.
Spider roams the Web, storing the URLs and indexing the keywords and text of each page encountered. Also referred to as a robot or crawler.