The web tracking feature tracks page visits: it shows who visits which pages and for how long.
It's connected with the email click tracking feature (which is inserted in your emails by the Gmail and Outlook plugin), so that when people click on a link in an email (not necessarily going to your website) the same cookie is saved or checked.
The website visits will appear in your Account timelines. After a contact has been identified by a cookie, the only prerequisite for this to come through is that the involved contact is added to the account.
How do I install the website tracking?
The "Website tracking script" is accessible in "Settings" > "Applications & integrations".
Scroll to "Integrations" and click on the "Show script" button to reveal the code.
Hit copy, then paste the script in entirety at the end of the head section of your website, right before or after the Google Analytics script.