Laptops and time machine
Laptops once used some of the free space available for a time machine back up. How do I enable (or disable) this function?
MacBook Pro Apple Silicon
You can't back up your computer to its own disk with Time Machine. However, your device saves local snapshots every so often to back up to the external drive when it is connected. The only way to stop this completely is to turn off Time Machine, but you can remove them if you want.
First, open Disk Utility. Select the Data partition, then click View > Show APFS Snapshots. You can then manage them as seen in the picture below-