Locksmithing is the science and art of making and defeating locks. Locksmithing is a traditional trade and in many countries requires completion of an apprenticeship. The level of formal education legally required varies from country to country from none at all, to a simple training certificate awarded by an employer, to a full diploma from an engineering college, in addition to time spent working as an apprentice.
An illustration of a German locksmith, 1451.
Locksmith, 2013
A lock is a mechanical or electronic fastening device that is released by a physical object, by supplying secret information, by a combination thereof, or it may only be able to be opened from one side, such as a door chain.
A typical modern padlock and its keys
Bronze lock in a form of scorpion from Nalanda, India, 10th century.
Medieval Gothic lock, from the 15th–16th centuries, made of iron, in the Metropolitan Museum of Art (New York City)
Drunk man's lock at the bottom (black lock) and a regular modern lock at the top