The timeclock is off until an owner turns it on in Store settings.
Once on: teammates clock in and out from the Timeclock tool, leaders see who's on the clock, and breaks follow the rules your store sets (including the stricter rules for employees under 18).
Payroll
Owners export a payroll CSV for any pay period: regular and overtime hours, break deductions, and flags for anything unusual. Give it to whoever runs your payroll.
Time records are kept for the period wage-and-hour law requires, so an old pay period is still exportable.