Audit. All machines is the default. The menu is every machine you can see.
Open Accounts server, then leave it. The machine menu says all machines. Two lines are from that visit: machine_opened (opened · overview) and machine_closed (viewed, with how long). Both name Accounts server. The menu reloads the list. It does not remove the lines.
Set the machine menu to Reception PC. The list reloads. Those two lines drop out, because they are about Accounts server. The page says no records for these filters. The visit is still stored. Set the menu back to all machines and both lines return. Clicking the machine name in a row sets this same menu.
One person is Show one person's audit lines. One kind of line is Show when someone opened a machine. A word in the line is Find an audit line by a word. The same trail while you are already on a machine is See who opened this machine.