What best describes the transfer of energy by electromagnetic waves?

The transfer of energy by electromagnetic waves is best described as radiation. This process involves the emission and propagation of energy in the form of electromagnetic waves, which can travel through a vacuum or various mediums without the need for any matter to facilitate the transfer. Examples of radiation include sunlight reaching the Earth and the heat emitted from a light bulb.

In contrast, conduction refers to the transfer of thermal energy through direct contact between materials, while convection involves the movement of energy through fluids (liquids and gases) due to temperature differences, causing the warmer, less dense portions to rise and the cooler, denser portions to sink. Insulation refers to materials or methods that reduce the transfer of heat, rather than describing a mode of energy transfer itself. Thus, radiation is the most accurate term for the transfer of energy via electromagnetic waves.