Google’s algorithm constantly scans the internet to better locate and index websites into its massive database. Every time a user searches for something on Google, the keyword (or keywords) are connected with that database, and Google’s aim is to produce results that most closely match a user’s search intent. 

However, while much is known about Google’s algorithm, and while Google does offer certain clues about how it ranks websites, it doesn’t provide a completely clear picture with all the details. A good SEO services agency is able to use the information Google has made public, and then use it to determine how to best structure your site so that you get as close to the #1 rankings as possible for a given subject.