Deleting your account and deactivating your Facebook account are both different things, so if you are confused about it I can explain you.
Deactivation of your Facebook account is temporary deactivation of your account and after deactivating your Facebook account you can anytime login on Facebook with same username and password and all your posts will be backed up.
Deleting Facebook accountis a permanent deletion and you can’t reactivate your Facebook account with same username and password. However, Facebook takes almost 3 months to erase all your posts from Facebook and if in between these erasing process if you log in to Facebook account your account deletion request gets canceled.
So, as you were asking you permanently deactivate or delete a Facebook account? Yes, you can delete permanently deactivate or delete a Facebook account.
"Hope it was informative"