Opensource.com - https://opensource.com/article/18/1/top-4-open-source-analytics-tools
If you have a website or run an online business, collecting data on where your visitors or customers come from, where they land on your site, and where they leave is vital. Why? That information can help you better target your products and services, and beef up the pages that are turning people away.
To gather that kind of information, you need a web analytics tool.