A handle, knob, or lever is the component of door hardware that is used to unlatch the door panel and pull it open or push it closed. There are many styles and finishes to choose from. There are three types of door handles:
are operated with a key cylinder on the exterior side of the door and a push or turn lock button on the interior.
have a push or turn lock button on the inside but not on the other.
have no locking mechanism.
A door latch is a shaft that protrudes from the edge of a door panel and into the door frame securing the panel in place. When the handle is turned, the latch retracts allowing the door to be opened.
Similar to a latch, a deadbolt is a shaft that protrudes from the edge of the door panel and into the door frame securing the panel in place. Residential interior doors are not equipped with deadbolts, and not all exterior doors have them either. Deadbolts are considered an additional form of security and are most often set apart from the handle assembly, which means that a door with a deadbolt needs an additional bore hole. Multi-point locking hardware systems provide even more protection than a latch and deadbolt combination, and new home automation
systems are available.
A deadbolt is operated by turning a thumb turn on the inside of a house and by a key cylinder on the exterior side.
These plates add strength to latches, deadbolts, and the door panel, which helps prevent a forced entry.