Search Engines

A search engine provide the means for humans to find things in all the millions of web pages out there. You type in a few words, click the search button and poof! you get a list of web pages. Search engines collect information from more than just Web Pages. They search through news groups, file servers and other sources.

When you use a search engine, you're not really searching the Internet, you're searching the database file the search engine built hours or even days ago. The Internet is just too big to search directly. A true search engine has two parts: the crawler and the search interface.

ENGINE COMPONENT: THE CRAWLER

A crawler is sometimes called a "spider". The crawler part actually downloads all the pages it can find, makes lists of the words in each page, counts how often they appear, and then builds a huge index file. This file 'ranks' the page based on the appearance of the word count.

ENGINE COMPONENT: SEARCH INTERFACE

A web page form is provided by the owners of the search engine to allow users to enter search terms and phrases. When the information is sent to the search engine, it looks up the words typed and displays all the links it found on the Internet that contain the word or words the user typed in.

 

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