Locks have many different options according to their usage areas and features. The types of locks used for interior and exterior doors are also systems that operate the locking mechanism for the most needed steel or similar door systems. The parts of the cylindrical locks can be changed at any time. Latched or keyed models can be used on exterior doors. The locks used in interior doors have a simpler structure. These are the systems that perform the process of locking and closing the interior doors with the key system.