What are kW and kWh?

Energy and Power can be confusing.  Energy is fuel, work, or ability to do work, and is measured in kWh, BTU, or Calories.  Power is how fast the energy is used and is measure in kW or horsepower.  

kW is kilowatt and kWh is kilowatt per hour.

For example, 2 kW of power for 3 hours uses 6 kWh.