A search engine is an automated tool which attempts to create a detailed and retrievable listing of Web pages.
All search engines work more or less in the same way.
The problem is that if you are looking for a general topic, search engines can turn back thousands of leads. No matter how carefully you craft your query, you'll probably have to sift through unrelated sites. It also takes time to check out every lead, even with those search engines that can create a bookmark file of the results. Search engines use different methodologies for performing searches. Search engines turn up leads based on objective criteria such as how many times a particular keyword is repeated within the text of a page, in a url, or page title.