Lock manufacturers fabricate and supply lock systems that provide security and prevent theft, unauthorized entrance or vandalism of residential and commercial buildings, vehicles, furniture cabinets, gates, storage facilities, factories and any other object or area that requires safety and protection. Locks are controlled and opened by a key, keycard, combination or with some method of keyless entry.

Locks are used on any door, window, cabinet, drawer, luggage or any other item that needs to be secured or closed. Door locks are the most common type, and prevent unauthorized entry to any kind of building, room or structure. Mortise locks are more secure but difficult and more costly to install, and cylinder locks are easily changeable and affordable, but provide minimal security. Other security locks like cabinet locks, cam locks and vending machine locks provide the same service but for different applications. There are many other security locks that differ greatly to the standard door lock, including cable locks, which are used to provide visible security to larger possessions that are stored outdoors like bikes and trailers. Today, there are several keyless locking devices. Combination locks and OEM locks require a correct number combination in order to open, and can be attached to any door, vehicle or cabinet. Electronic locks are the most technologically advanced locking system used today and are equipped with a magnetic card reader or keypad. They are common in workplaces with high turnover rates, high security measures or buildings where the authorized personnel are constantly changing.
There are three main types of locks: mechanical, electronic and biometric. Mechanical locks include pad locks, mortise locks and cylinder locks, all three of which are most commonly seen in residential and commercial buildings on doors and door frames. Mechanical locks are made of metal and are either opened with a key or the correct combination, which is made when the spinning locks are aligned perfectly. Some are designed for bathrooms, bedrooms or offices within the interior of a building, while others, usually mortise locks, which are harder to pick or break, are employed to secure doors to the outside. Hotels and higher security workplaces use electronic lock systems, which are keyless. In order to open them, the user must have an access code or password to type into a keypad or a plastic magnetized card in order to open the bolted door. These are useful when the authorized users of the locking systems change often. Biometric locks are the most advanced and expensive locks available today, and they also provide the highest amount of security. Government agencies and areas that require the highest safety from unauthorized entry employ these door locks, which require a fingerprint scan, voice recognition or a retinal scan in order to open. This method does not allow key or code theft, and ensures that only the correct personnel may enter an area.
The main securing component of a lock system is the bolt; a solid, strong steel or titanium rod piece with a round profile that, when the mechanism is locked, is inserted into the door frame to prevent the door from separating from the frame. They may be spring operated or a dead bolt, which is the most secure form of bolt. A dead bolt is more secure than a spring lock because it cannot be opened unless the locking mechanism has been unlocked. Electronic locks have computer chips that program the door to always automatically lock after closing. The bolt can be opened and closed by the locking mechanism. Most often, the lock will be made up of a pivoted, rotary or sliding bolt protected either by a movable or stationary item.One of the oldest types of locks mechanisms is the warded lock. It has a notched key that slides the bolt backward and forward, and the notches must match up in order to open. Another type of mechanical key lock is a tumbler lock. This lock has pieces of metal that prevent the bolt from moving by falling into place. The key is serrated to raise the metal pieces, or tumblers, to the appropriate place for the bolt to move and open. Combination locks were the first keyless locks invented and consist of disk tumblers that must be aligned properly for the spindle to slide out. The majority of these locks have a dial that turns both counterclockwise and clockwise to certain numbers in order to be opened. They are often seen on padlocks, strong room doors and safes. A newly developed lock mechanism distributed by lock suppliers is the magnetic key lock. Magnets repel spring-loaded pins when the key is inserted, and this works similarly to the serrated key of a tumbler lock.
In order to pick out the correct lock from a lock supplier for a specific application, a few things should be taken into consideration. An electronic lock with access keys or codes may be better than using traditional mechanical locks and keys when involved with a number of people, so that keys won't disappear or get misplaced. Secondly, the purpose of the lock is very important as to which one should be used. Some applications require very high security or durable locks, while others need a less reliable lock, or the application may need either a door or portable lock. Lastly, when selecting a lock, the convenience of it should be taken into consideration; how often will it be used? How quickly will access be needed? For example, a fingerprint scanner may be fast, but if hands are not free, it will prove difficult to use.