To turn off Facebook, you have two main options: deactivate or delete your account. Deactivating your Facebook account temporarily hides your profile from others but allows you to reactivate it later. To deactivate:

1. Click your profile picture.
2. Go to Settings & Privacy > Settings.
3. Select Accounts Centre > Personal details > Account ownership and control > Deactivation or deletion.
4. Choose Deactivate account and follow the prompts.

Deleting your Facebook account permanently removes your profile and data, and you lose access to Messenger. To delete:

1. Follow the same path: Profile picture > Settings & Privacy > Settings > Accounts Centre > Personal details > Account ownership and control > Deactivation or deletion.
2. Select Delete account and follow the steps.
3. You can undo deletion within 30 days by logging back in; after that, the deletion is permanent.

Deactivation allows you to keep using Messenger; deletion removes messaging access. This process can be done on both desktop and mobile apps with similar navigation steps.