How does Google Work?
There are three things that Google does to give you great results:
Crawling the web. Google starts by “crawling the web” to see what is on each website. It looks at the links, and the sitemap of a company so that it can know what is available on the internet.
The crawlers is separate from AdWords so that it does not have a conflict of interest. It does this simply to have the most up-to-date and accurate knowledge of what is on the web.
Indexing is when the Googlebots, the computers that crawled the web pages, sort and order the information that is on the web pages so that it knows which websites to show that are the most relevant.
When a user puts in a search request, Google uses over 200 factors to try and figure out what the best page would be to return as a result. Because the page rank is such an important factor in how high your page will show on a Google search result it is important to know the rules to play in the game. Follow this link to get a list of rules.
Here is a link to the page I used as a resource.