What is the exact function of piwik?

Piwik is the leading open source web analytics software, used by more than 460,000 websites. It gives interesting reports on your website visitors, your popular pages, the search engines keywords they used, the language they speakā€¦ and so much more.

Piwik aims to be an open source alternative to Google Analytics.

Piwik is a PHP/MySQL software that you download and install on your own web server. At the end of the five minute installation process you will be given a JavaScript tracking code. Simply copy and paste this tag to any websites you wish to track (or use an existing plugin to do it automatically for you) and access your analytics reports in real time. Piwik is fully featured and Piwik Consultants can help with Support Plans and Custom Development, White Label options, Google Analytics Data Import, and more: contact Professional Services.