This document discusses the three main methods of heat transfer: conduction, convection, and radiation. Conduction involves the transfer of heat between objects in direct contact, where heat moves from warmer to cooler areas. Convection refers to the transfer of heat by the circulation of fluids like air and water. Radiation involves the transfer of heat through electromagnetic waves, such as heat from the sun or a fire warming nearby objects. The document provides examples of each type of heat transfer and explains how temperature differences drive the transfer of heat between objects.