Date Added: May 2011
The Internet has become a vast information source in recent years and can be considered as the world's largest digital library. To help ordinary users find desired data in this library, many search engines have been created. Each search engine has a corresponding database that defines the set of documents that can be searched by the search engine. Usually, an index for all documents in the database is created and stored in the search engine. For each term which can represent a significant word or a combination of several (usually adjacent) significant words, this index can identify the documents that contain the term quickly.