After you sign in, this system records which pages you open, how long each one stays open, and whose page it is when you open a colleague's performance page. It does not record what you type or click. Durations come from your browser and are approximate: this measures page-open time, not work output.
Admins can see everyone's activity, including which colleagues' pages you opened; you can see your own under Settings → My activity (Activity log for admins). It is kept for 90 days in the app and can remain in backups for up to about 120 days.