Electrocution or electric shock is when electricity passes through something living. It happens when the human body gets in contact with electric current. The word "electrocution" originated as a portmanteau between electricity and execution, referring to those executed by electric chair, but has evolved to describe any fatal encounter with electricity. Nonfatal encounters are called electric shocks, or simply a "shock".
The human body is well suited to withstand voltage, but not very much electric current (measured in Amperes). If the electric current is strong, it can stop heartbeat and cause death. Very high voltage and/or current can cause severe burns and even fry the victim alive.