Time Machine
Mac backups made automatic.
1. Get an external drive
USB drive 2 TB or larger. About $60-80 at any electronics store.
2. Plug it in
Mac asks if you want to use it for Time Machine. Click Use as Backup Disk.
3. Automatic backups
Time Machine backs up every hour while the drive is plugged in.
4. Recover a file
Open the menu bar Time Machine icon. Enter Time Machine. Scroll to find old versions.
5. Recover everything
If your Mac fails, plug the drive into a new Mac. Pick Restore from Time Machine.
6. Verify
System Settings, General, Time Machine. Check the date of the last backup.
Pair Time Machine with iCloud for two layers of safety. Drives can fail too.