Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Energy SciPack. It provides a conceptual and real-world understanding of the relationship between thermal energy, heat, and temperature. The thermal energy of a material consists of the disordered motion of its atoms or molecules. Thermal energy can be transferred through materials or from one material to another by conduction (the collisions of atoms), or across space by radiation. If the material is fluid, convection currents aid the transfer of thermal energy (convection). When thermal energy is transferred it is called heat. Temperature is a measure of the average kinetic energy of atoms and molecules in a material.