Conduction is the process by which heat or electricity is transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions. Convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat. Radiation is 1.) the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization. 2.)divergence out from a central point, in particular evolution from an ancestral animal or plant group into a variety of new forms.
