When you are searching for information on the World Wide Web, you will find many different search engines. Why so many? Various search engines collect and categorize information in different ways. Information that might be on one search engine, may not be on another.

It's like libraries. Not all libraries have all the same information. For example, a law library does not have the same information as a medial library. Both these libraries have totally different materials than a public library.

Because of this, it's a good idea to use several search engines in your search. That way, you can be sure to get extensive results.