Each of the major search engines differs in some small way. Google is the king of search engines, in part because of the accuracy with which it can pull the results from a search query. Sure, Google offers all kinds of extras like e-mail, a personalized home page, and even productivity applications, but those value-added services are not what made Google popular.

What turned Google into a household word is the accuracy with which the search engine can return search results. This accuracy was developed when the Google designers combined keyword searches with link popularity. The combination of the keywords and the popularity of links to those pages yields a higher accuracy rank than just keywords alone.

However, it’s important to understand that link popularity and keywords are just two of hundreds of different criteria that search engines can use in ranking the relevancy of web pages.