Heat flow refers to the transfer of thermal energy from one object or area to another due to a temperature difference. This process occurs in three main ways: conduction, convection, and radiation. In conduction, heat moves through materials by direct contact, while convection involves the movement of fluids (liquids or gases) carrying heat with them. Radiation, on the other hand, involves the transfer of heat through electromagnetic waves, such as sunlight warming the Earth. The rate of heat flow is influenced by factors like the temperature difference, the materials involved, and their physical properties. For example, metals typically conduct heat better than insulators like rubber or wood. Understanding heat flow is essential in various fields, including engineering, meteorology, and environmental science, as it helps in designing efficient heating and cooling systems.