A Watt (W) is a unit of electric power in the International System of Units. It refers to a specific amount of power.
A Watt-hour is a unit of measurement for energy consumption in the International System of Units. Watt-hour, which is symbolized Wh, is defined as one watt of power expended for one hour of time. For example, a 5.6 kWH system is one that provides 5.6 kilowatts in an hour.