A patio sliding door lock is a type of lock that is designed to be used on sliding doors, typically doors that lead to a patio or deck. These locks are typically installed on the top and bottom of the door and can be locked and unlocked using a key or a thumbturn. Some patio sliding door locks may also include additional features such as a deadbolt for added security. It's important to choose a patio sliding door lock that is sturdy and reliable to ensure the security of your home.