What is the concept of "latent heat" in the context of steam?

Latent heat refers to the amount of energy that is absorbed or released by a substance during a phase change, without any change in its temperature. In the context of steam, it specifically pertains to the energy required to convert water into steam at its boiling point.

When water is heated to its boiling point, it requires additional energy to change from liquid to vapor, even though the temperature remains constant during this phase transition. This energy is referred to as the latent heat of vaporization. It plays a crucial role in various applications, such as in boilers, where steam is generated for heating, power generation, and other processes.

The other choices focus on different energy aspects that do not pertain directly to the concept of latent heat in steam. For example, while condensation does involve the release of heat, it is not the latent heat associated with vaporization. Similarly, combustion energy and heat retention by boiler structures address different phenomena rather than the specific heat transition involved in producing steam. Therefore, the choice concerning the energy required for the phase transition of water to steam at constant temperature accurately encapsulates the essence of latent heat.