How Search Engines Work

Search engines have programs called spiders which visit web pages to determine your website is about and contribute to the ranking of your site when someone searches.

Spiders, or web crawlers, scan the content of web pages. They take the results of their scan and analyze. Links in the website are stored. Later other spiders crawl the linked pages. The more links from other websites your website has, the more frequently your website is crawled by the spiders and in theory rated higher in the ranks of similar sites.