Glossary
Savings history
A readable record of the space Disk Housekeeper saved on your Mac.
After a clean, it helps to see what was actually removed rather than remembering a feeling about the disk. The savings history is that record. It belongs to the machine the app ran on. A marketing page that prints a typical gigabyte number would be inventing one, so this site does not.
Read it next to the menu bar free-space readout. If they disagree, files may still be in the Trash, which still uses space, or you may be looking at purgeable space. The steps are in Read a savings history.