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How does heat differ from temperature?

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heating In a thermoelectric generating system a heat source—usually fueled by coal, oil, or gas—is used within a boiler to convert water to high-pressure steam. The steam expands and turns the blades of a turbine, which turns the armature of a generator, producing electric power. A condenser converts any remaining steam to water, and a pump returns the water to the boiler.

It is a common misconception to use the terms heat and temperature interchangeably; however, they represent distinct physical concepts.

Heat is energy in transit. It is defined as energy being transferred from one body to another due to a difference in temperature. Because it is energy in motion, it is incorrect to speak of the "heat in a body"; instead, heat describes the process of energy transfer between systems.1

Temperature, by contrast, is a measure of the hotness or coldness of a body, expressed on scales such as Celsius or Fahrenheit. It serves as an indicator of the direction in which heat will spontaneously flow: energy moves from a body at a higher temperature to one at a lower temperature. When two objects reach the same temperature, they are in thermal equilibrium, and the net flow of heat between them ceases.213

In summary, while heat is the energy being transferred, temperature is the measure that determines the direction of that transfer.21