The extent of the search and method of searching varies by search engine, as discussed further below. The search engine will then provide you with the results of the search, or potentially relevant links to information on the Web. Most of the search engines currently available are general and seemingly all inclusive in the web sites they cover, such as Alta Vista , Open Text and Lycos . There is an emerging category of search engines which limit searching to Web sites on specific topical areas, such as Lawcrawler . Additionally, there is a relatively new category of engine which utilizes the searching capabilities of multiple robot searchers simutaneously.
Some search engines contain listings of subjects, which resemble subject guides.
However unlike the subject indices discussed below, these exist for searching and not browsing. Subject Indices are listings of topical areas with links to information on the Web in those areas. These indices usually are arranged topically by menus. One starts with a broad menu listing, proceeds through links to menus with more specific categories of information, and eventually arrives at links to specific web sites. Subject indices organize vast contents of information on the Internet and then make it available in a hierarchical form for browsing.