The term 'latent heat' refers to:

The term 'latent heat' specifically refers to the heat transfer that occurs during a phase change of a substance without a change in temperature. This means that while a substance may absorb or release heat energy during processes such as melting, freezing, boiling, or condensing, its temperature remains constant throughout these transitions.

For example, when ice melts to become water, it absorbs heat from its surroundings, yet the temperature of the ice-water mixture does not increase until the entire ice has melted. This characteristic is what differentiates latent heat from other forms of heat transfer, where temperature changes accompany the heat transfer.

The aspect of latent heat being related specifically to phase changes—without any temperature change—is essential for understanding various thermodynamic processes, including those experienced in steam systems and refrigeration cycles. Essentially, latent heat plays a crucial role in energy transfer during these processes and is fundamental in the study of heat engines and refrigeration systems in the context of power engineering.