Google Trends is a report of an array of counters. Wait! What? When we make a search for something using Google or Google related applications, Google stores that term or keyword (it could be phrase) in a DBS (data base system).
Also, Trends is one of the best and most versatile tools available for SEO. It is the marketing equivalent of the Leatherman or Swiss Army knife. If you could only use one SEO tool to develop an Internet marketing campaign, this product would be a serious contender.
For example, if another identical word or sentence/phrase is searched using Google search engine, this will increment the stored value of that word or sentence/phrase with +1. It is a counter of that word or sentence.
This simple process keeps track of searching behavior in a determined period of time, and a ranking could be made out of this. That is exactly what Trends does: dynamically ranks searches by their frequency and draws up a ranking chart at the end of the year (or real time by the case).
Using Google search engine amplitude, Google Trends divide terms or sentences in classes or domains of interest. This way, we could follow the movie from top, the news from top, the social networks from top, and so on.
This segregation is also done by country, using IP addresses.