A goal of a search engine is to provide its users with the most relevant web page based on the users search queries. In order to do this, a search engine's underlying functionality is an algorithm which takes thousands of factors, with different weights, found directly on a web page, and orders them in the search results based on their relevancy to the keyword or keyword phrase searched.

Search engines pair your search criteria with the most relevant search results incredibly fast because they already know most all of the web pages available and accessible online. Search engines have what are commonly known as “spiders” which scour the Internet and “index” every page found on the web to be ranked based on their relevancy to search queries.