A Kensington lock is a security device that attaches a cable from a computer to a stationary object such as table. It is similar to a bicycle lock that attaches a bicycle securely to a railing. This security device deters the potential casual theft of a notebook, or other devices, in public areas such as cafes, airports, and school libraries.
Most notebooks manufactured since 2000 have a Kensington slot, or K-slot, somewhere on the case. One end of the security cable has a lock that attaches to this K-slot with either a keyed lock or a combination padlock. The other end of the cable can be looped around a table leg or other heavy object to keep the notebook in place.
Figure : Kensington lock with keys