To do this, they look for the location and frequency of keywords and phrases in the web page document and, sometimes, in the HTML META tags. They check out the title field and scan the headers and text near the top of the document. Search engines are best at finding unique keywords, phrases, quotes, and information buried in the full-text of web pages. Because they index word by word, search engines are also useful in retrieving tons of documents. If you want a wide range of responses to specific queries, use a search engine.
Search engines no longer limit themselves to a search mechanism alone.
Across the Web, they are partnering with subject directories, or creating their own directories, and returning results gathered from a variety of other guides and services as well. This page updated 01 February 2001 by Ellen Chamberlain , library webweaver.