Heat is a form of energy that is transferred as a result of a temperature difference between two objects. It can flow through three different mechanisms: conduction (when heat flows through a stationary solid), convection (when heat is transferred through the movement of fluids), and radiation (when heat travels through electromagnetic waves).

The amount of heat transferred is related to the temperature difference between the objects and the thermal conductivity of the material the heat is moving through. The study of heat and its related properties is known as thermodynamics, and it plays a crucial role in fields ranging from engineering to meteorology.