A traditional set of lock picks. The two tools on the left are tension wrenches

Lock picking is the act of unlocking a lock by analysing and manipulating the components of the lock device, without the original key. Although lock picking can be associated with criminal intent, it is an essential skill for a locksmith. Lock picking is the ideal way of opening a lock without the correct key, while not damaging the lock, allowing it to be rekeyed for later use, which is especially important with antique locks that would be impossible to replace if destructive entry methods are used.

Usually it is possible to bypass a lock without picking it. Most common locks can be quickly and easily opened using a drill, bolt cutters, bump key, or a hydraulic jack. The hasp, door, or fixture they are attached to can be cut, broken, or otherwise removed.

A lock that offers high resistance to picking does not necessarily make unauthorized access more difficult, but it will make surreptitious unauthorized access more difficult. They are often used in combination with alarms to provide layered security.

Some people enjoy picking locks recreationally, because they find it brings high satisfaction and is an enjoyable way to pass the time; it also has hack value.

Source : wikipedia.org