Search Engine, computer software that compiles lists of documents, most commonly those on the World Wide Web (WWW), and the contents of those documents. Search engines respond to a user entry, or query, by searching the lists and displaying a list of documents (called Web sites when on the WWW) that match the search query. Some search engines include the opening portion of the text of Web pages in their lists, but others include only the titles or addresses (known as Universal Resource Locators, or URLS) of Web pages. Some search engines occur apart from the WWW, indexing documents on a local area network (LAN) or other system.
