Google Analytics is a web analytics service offered by Google that tracks and reports website traffic. This can be used to track session duration, page views, bounce rate and more.
You can set up Google Analytics here: https://analytics.google.com/analytics/web/
Your Google Analytics Code should start with a UA and look something like this: UA-000000-2
Here is a guide with further information on how to find it - https://support.google.com/analytics/answer/1008080?hl=en
If you would like to track traffic to your website, please set up Google Analytics first and then send your Google tracking ID to firstname.lastname@example.org