HOW SEARCH ENGINE WORKS? Unlike humans, search engines are text-driven. Search engines crawls the Web, looking at particular site items (mainly text) to get an idea what a site is about. This brief explanation is not the most precise because as we will see next, search engines perform several activities in order to deliver search results – crawling, indexing, processing, calculating relevancy, and retrieving. 1. Crawling First, search engines crawls the Web to see what is there. This task is performed by a piece of software, called a crawler or a spider (or Googlebot, as is the case with Google). Spiders follow links from one page to another and index everything they find on their way. 2. Indexing After a page is crawled, the next step is to index its content. The indexed page is stored in a giant database, from where it can later be retr...