Locksmiths use both lock picking and bumping to legally gain access to properties and vehicles, where it is permissible to do so by law and they have the property owner's consent. Lock picking is generally the less damaging of the two, although it might be necessary to change the locks afterwards.

A locksmith is a professional tradesperson who works with locks for a living – whether that be fitting locks, opening locks, carrying out lock repairs or any other lock-related jobs. A door locksmith deals with the locks on buildings (including both doors and windows).

If you've ever locked yourself out of your house, the person to call for help is a locksmith. When you need a new copy of your apartment key, you can also visit a locksmith. The word comes from lock and smith, from the Old English smið, "one who works with metal."

The first all-metal locks appeared between the years 870 and 900, and are attributed to English craftsmen. It is also said that the key was invented by Theodorus of Samos in the 6th century BC. 'The Romans invented metal locks and keys and the system of security provided by wards.