notes stored on your Mac
You can store notes on your Mac instead of in an online account (such as your iCloud account). If you store notes on your Mac, they aren’t available on any of your other devices.
Notes stored on your Mac appear under On My Mac in the sidebar. If you don’t see On My Mac in the sidebar, you can enable it.
Choose Notes > Preferences, then select the “Enable the On My Mac account” checkbox.
Note: If you later disable the On My Mac account, notes in your other accounts (such as iCloud) are not affected.