A door knob is a round or oval handle used to open and close doors. It is typically mounted on a door and can be turned to disengage a latch, allowing the door to swing open. Door knobs come in various materials, such as metal, plastic, or wood, and can have different designs to match the style of a home or building. Most door knobs are designed to be easy to grip and turn, making them user-friendly for people of all ages. Some door knobs also include a locking mechanism for added security, which can be useful in residential settings. Related items include door handles and locks.