exactly IS a spider

[pavankumar]

hi..
Plz u give me answer what exactly IS a spider?

[Amy.Sarin]

Spider is a program that automatically fetches Web pages, ‘crawls’ links throughout the Internet, grabbing content from sites and adding it to search engine indexes. :)

Spiders are used to feed pages to search engines. It's called a spider because it crawls over the Web. They are also known as ‘bots’, ‘ants’, ‘web spiders’ ,’web crawler’ etc..