The Watt hour (Wh) is a unit of energy that measures the amount of electric energy consumed or produced over a period of time. Specifically, it quantifies the energy usage or generation when power is applied at a constant rate of one watt for one hour. The symbol for Watt hour is Wh, and it is commonly used in both practical and scientific contexts to express the consumption of electricity by appliances and devices. For larger quantities, the kilowatt-hour (kWh) is often utilized, where one kWh equals 1,000 Wh. Understanding Watt hours is crucial for assessing the efficiency of electrical systems, managing energy consumption, and evaluating the performance of renewable energy sources, making it a vital concept in today's energy-conscious world.