History
How your free space changed over time, and how much Cachet has moved to the Trash.
History in the sidebar shows each scan and cleanup: the date, free space, how used space changed, what was found, and what was moved to the Trash. The cards at the top total the space moved to the Trash with Cachet, when tracking started, and the number of scans.
History stays on your Mac, in Cachet's own storage, and is removed if you delete Cachet.