(W) The SI unit of power.
Definition: 1 watt is equal to a power rate of one
joule of work per
second of time or in electrical terms it is the power produced by a current of one
ampere flowing through an electric potential of one
volt.
Power is the rate at which work is done, or the rate at which
energy is expended and is used both in mechanics and in electricity.
The unit is named for James Watt, a British engineer.