A door lock is a mechanical or electronic device used to secure a door, preventing unauthorized access. It typically consists of a bolt that fits into a strike plate on the door frame, and it can be operated using a key, combination, or keypad. Door locks come in various types, including deadbolts, padlocks, and smart locks, each offering different levels of security. The primary purpose of a door lock is to protect property and ensure safety. When locked, it creates a barrier against intruders. Proper installation and maintenance of door locks are essential for their effectiveness, as worn or damaged locks can compromise security.