Did you know that there are many types of door locks? Here are the most common types: Door handle locks They are usually found on bathroom doors. The reason why they are usually installed in the bathroom is because they are very insecure as you can easily pick them. They work by preventing the handle from rotating. Keyless From their name, they are keyless. The locks are usually locked and unlocked using a unique code that is entered into a keypad. The cool thing with the locks is that they are very secure.