SPIDER

Small piece of software (also known as a (ro)bot), used by some search engines  to index Web sites . Spiders search the Web  to find URLs  that match to the given query string  .

A program that automatically fetches Web pages. Spiders are used to feed pages to search engines. It's called a spider because it crawls over the Web. Another term for these programs is webcrawler. Because most Web pages contain links to other pages, a spider can start almost anywhere. As soon as it sees a link to another page, it goes off and fetches it. Large search engines, like Alta Vista, have many spiders working in parallel.

A software robot that serves a search engine by exploring the net,collecting web page addresses and page contents,and following links from them to other addresses to collect still more web information.Also known as a worm or crawler.

An automated program which searches the internet.