Large selection of different locks represented now in stores. Each of these devices has its own level of protection and reliability. There are several types of locks, depending on the mount. Padlocks are also often called the hanging. This lock is as simple to install and change, but worst of all that it is protected from breaking force, enough to break the crowbar. Such devices are typically installed on the garage doors and gates. Degree of reliability is low. On the origin and development of the art manufacturing padlocks, very little is known. Chinese scientists Hsing-Hui and Huang Hun Sen Yang defended in 2004 doctoral dissertation on this subject conducted an analysis of different padlocks on the types and arc-shaped and protected springs. Despite the lack of historical records, in their opinion, the padlocks were produced in ancient China, then there is at least a couple of millennia ago. However, some Western scholars believe that locks in China appeared slightly later than in Western Europe. Believe that the design of padlocks came about in II-III centuries in the Roman Empire. There is a substantial similarity between the locks manufactured in ancient China and in Scandinavia dating from the end of the Viking era, despite the fact that the influence of the Roman Empire to their culture is ruled out. In cultures around the padlock often gave different forms of amulets, talismans and animals. It was believed that they were able to attract good fortune, luck and wealth in the house. Rim locks are installed inside the door. This castle is much more protected from the force picking the more than fasten securely the lock the door. Consignment lock key closed from the outside, but inside, the key or the rotary latch. Castle superimposed type, used as a supplementary device, often equipped with a front door - when you install it almost does not violate the integrity and strength of the door leaf and can be easily mounted. The reliability of such locks is mean. Electronic locks have the principle of mortise devices. Mortise locks are located immediately inside the door. Most protected from the force hacking. Security of the the lock depends primarily on the strength of the door. Attention is noted to the lock mechanism that should be located closer to the outside of the door for the protection mechanism may require additional armored plating. This lock is more difficult to install a door that has no seat for such lock.