Final answer:
The heat transfer within a solid due to a temperature gradient is conduction, where heat moves through the solid by direct contact between particles.
Step-by-step explanation:
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes.
Engineers also consider the transfer of mass of differing chemical species, either cold or hot, to achieve heat transfer. The type of heat transfer that occurs across a temperature gradient within a solid is known as conduction. In conduction, heat is transferred through stationary matter by physical contact, without any overall transfer of mass.
A classic example of conduction is how heat moves from the hot burner of a stove through the bottom of a pan to the food inside it. This is distinctly different from convection, which involves the macroscopic movement of a fluid (such as water or air) transferring heat, and from radiation, which is heat transfer by electromagnetic waves such as infrared radiation or visible light.