@variablepulserate Snapshots came along with High Sierra and are taken every hour by time Machine, they are generally no more than 2 GB maximum. Prior to APFS, only laptops saved local backups (as they were previously known) but all Macs using APFS create snapshots. Snapshots are also saved very quickly.
More info here: https://www.lifewire.com/roll-back-apfs-snapshots-4154969