When you need to find information on the Internet is more than likely that first thing does is connect to a site such as google or yahoo or msn. But such see did you not know that these sites that are specially designed to help us find information by Web media are known as search engines. A Web search engine is used to look up information on the World Wide Web. The search results are usually presented in a list that is sorted by relevance. The information may consist of a combination of web pages, images, videos, information and other types of files. Like the famous google search engines generally work through the creation of an index.
An index is basically like a database that is created by two separate programs. The first program known as a spider (Spider) search all over the Internet and catalogs all the pages that exist on the Internet and also catalogued changes in pages that they are already in the index. Then another program known as indexer (indexer) reads these documents and creates an index based on the words contained in each document. Each search engine uses a proprietary algorithm to create its indices so that, ideally, only meaningful results for each query are returned. When you visit a search like google engine, you enter at least one word to run your search. This word is compared against the most recent index and the results are presented in the page in order of relevance.