How is heat transfer defined?

Heat transfer is defined as the movement of thermal energy from a region of higher temperature to a region of lower temperature. Therefore, the correct answer reflects the fundamental principle of thermodynamics, which states that heat naturally flows from hot substances to cooler substances. This natural flow occurs in various forms, including conduction, convection, and radiation.

When considering heat transfer in practical applications, it’s crucial to understand that this process is vital for energy efficiency and management in utility services, helping to maintain system stability and performance. Overall, the concept of heat transfer is foundational in the study of thermal dynamics and energy management across various industries.