Door locks refer to any mechanical, magnetic or electrical mechanism or device that prohibits unauthorized entrance into a private or secure location. There are several different kinds, all with varying degrees of security, cost and ease of installation—most require the hiring of a lock professional.
There are many different kinds of door locks, all of which fall under two main categories: passage locks, which are interior locksets that only provide a closing latch, and privacy locks, which secure a door from the outside, inside or both. All locking mechanisms control a type of bolt, which is a solid piece of metal that emerges from the door into the door frame. There are both deadbolts and spring-operated bolts, both of which are usually made of steel and have a round profile. Some cylinder locks only have a very small, short and thin spring-loaded bolt that can easily be broken. Deadbolts, however, have no spring and are much more secure. They are unlocked only from the inside, never the outside, and use a lever that is twisted to unlock it. A mortise lock uses a deadbolt, and is more secure than a cylinder lock. However, a mortise lock is more costly and difficult to install, while a cylinder lock is easily changed and can be installed by anyone.
