How is heat transfer by radiation different than transfer by convection or conduction?

Heat transfer is the movement of thermal energy from one body to another. There are three main ways in which heat can be transferred: conduction, convection, and radiation.

Conduction is the transfer of heat through a solid material by direct contact between the particles of the material. It occurs when two objects are in contact with each other and heat is transferred from the hotter object to the cooler object. Conduction is the main way in which heat is transferred through solid materials, and it requires that the two objects be in physical contact.

Convection is the transfer of heat through a fluid (such as a gas or a liquid) by the movement of the fluid itself. It occurs when a fluid is heated, becomes less dense, and rises, while cooler, denser fluid sinks. This circulation of the fluid carries the heat from one place to another. Convection is the main way in which heat is transferred through fluids, and it requires that the fluid is in motion.

Radiation is the transfer of heat through space by electromagnetic waves, such as infrared radiation. It does not require a material medium to transfer the heat and can occur through a vacuum. Radiation is the main way in which heat is transferred through the vacuum of space, and it does not require the physical contact or motion of a medium.

In summary, conduction involves the transfer of heat through direct contact between particles, convection involves the transfer of heat through the motion of a fluid, and radiation involves the transfer of heat through electromagnetic waves.