A positive connection is one in which a change (increase or decrease) in some variable results in the same type of change (increase or decrease)in a second variable. The positive connection in the figure below for a cooling coffee cup implies that the hotter the coffee is the faster it cools.
The power consumption of small devices is usually measured in Watts, and the power consumption of larger devices is measured in kilowatts (kW), or 1,000 Watts. Electricity generation capacity is often measured in multiples of kilowatts, such as megawatts (MW) and gigawatts (GW).
Watts measure power--kilowatt-hours measure energy. When you get your utility bill, the electricity you've used is measured in kilowatt -hours (kWh). While a watt is a measure of power, a kWh is a measure of energy. Energy is defined as the capacity to do work, such as creating heat, light, or motion. If you run a 60-watt lightbulb for one hour, you've used 60 watt-hours, or 0.06 kilowatt-hours, since a kWh is 1,000 watt-hours.