They are not! The Master Password is used to generate all the other keys, including the Owner Key. The confusion is usually around the fact that we don't even allow you to view your Master Password through steemit.com. That's because the only reason you should ever really be using your Master Password is when you are going through the account recovery, in which case you should be retrieving the Master Password from your safe storage. The Master Password is the password you get upon signing up. You should then take that password, go to your Steemit.com wallet, retrieve all the other keys, and only use those keys going forward. Hope that helps!