The World Wide Web gives access to a huge amount of information recently estimated at over 1000 million pages.
Some experts consider that the Web doubles in size every four months.
Add to this the fact that the Web is not organised like a library, and is a medium on which anyone can publish anything, and it is no wonder that many users become frustrated at not being able to track down quality information on the Web and yet overwhelmed by the quantity that they often find. But there are at least 3000 search engines, both general and specialised. Even the major search engines index at best only about a third of documents on the Web Different search engines do not necessarily index the same Web pages Different search engines have different frequency of updating Some search engines search all the text of a document whereas some search only the first few sentences, so different engines give different results and different relevance rankings Search engines are developing all the time. Click on Search Engine Listings. Some searchers prefer to use the smaller engines so that they are not overwhelmed with results, but as long as you use the appropriate keywords and the engine ranks the results, even a return of several million hits is not really a problem as you should only need to look at the first few.