What does the term 'latent heat' refer to?

The term 'latent heat' specifically refers to the heat required to convert a substance from one phase to another, such as from solid to liquid or from liquid to gas, without any change in temperature. This process occurs during phase transitions where the energy input goes into breaking the intermolecular bonds rather than increasing the temperature of the substance.

For example, when ice melts into water, latent heat is absorbed without raising the temperature of the water during the phase change; similarly, when water vaporizes into steam, the temperature of the water remains constant until the phase change is complete. This concept is essential in understanding thermal energy transfer in various engineering applications, as it affects calculations involving heating, cooling, and energy efficiency. Other options, while related to thermal processes, do not accurately define latent heat, as they pertain to different aspects of thermal energy and phase changes.