Google Analytics is a rich web app that allows website owners to get a huge range of statistics and reports on traffic.
With a Google Account you can access Google Analytics, and there are easy to follow instructions about how to add the necessary code to your site so the traffic data is collected. You can then easily see statistics like traffic sources, visitors, page views and much more. You can track the growth of your traffic using the compare tool and set up segments to analyze specific type of traffic.
As well as using the web app itself, Google Analytics can send out email reports with statistics you choose. It's an incredibly useful tool which can help you set up Key Performance Indicators and goals for your website.
For new users, Google Analytics may appear confusing, but there is a ton of easy-to-find literature out there to help you learn the jargon. Google Analytics is a really well-organized application that absolutely adheres to the clean and functional design aesthetic of the family of Google Apps.
Google Analytics is the best free way to track traffic on your website. The statistics you get can be almost as simple or in depth as you need.