In terms of heat transfer, what does "radiation" specifically refer to?

Radiation specifically refers to the transfer of heat by electromagnetic wave motion. This process occurs without the need for a physical medium, meaning heat can be transferred through a vacuum. For instance, the warmth from the sun reaches the Earth through the vacuum of space, illustrating how radiation effectively transmits thermal energy across distances. It is distinct from other heat transfer methods like conduction, which requires direct contact between materials, and convection, which involves the movement of fluids. Understanding this concept is crucial in fields such as building science, where managing heat transfer effectively can influence energy efficiency and indoor comfort.