Google Analytics is to make an analysis of your website traffic, is the measurement, collection, analysis and evaluation of website user data with the aim to understand the usage, and optimise the website based on the information. It uses a data to provide all the information in the reports, which come from sources like the HTTP request of the user, browser/system information and sets and reads first-party cookies on your users' browsers, in order to obtain user session and any ad campaign information from the page request.
We can find some web analytics tools like free Open source products (Piwik), commercial products, products offered by the Internet host and Google Analytics. Also we can make a segmentation of web analytics data geographically, per page of reference, keywords of the search engine, time stamp and session time, technology and for the page views.
Google Analytics is good for your business because it allows you to measure sales and conversions, gives you information about your visitors, like how they use your site, how they got there and what you can do to keep them. Among its functions we find tools for analysis, content analytics, social networks, mobile, conversion and advertising.