To distinguish between good conductors and poor conductors of heat.
Conduction, radiation, and convention are the three main ways that heat energy moves from place to place. Conduction involves two forms of energy, namely heat or electricity. Heat conduction occurs when two objects are in contact with each other. Heat energy is transferred from one to the other. Heat energy travels from a hot point to a cold point in heat conduction. Conduction is the process by which heat energy is transmitted through collisions between neighbouring atoms or molecules. Conduction occurs more readily in solids and liquids, where the particles are closer together than in gases, where particles are further apart. The rate of energy transfer by conduction is higher when there is a large temperature difference between the substances that are in contact.
A good conductor or conductor of heat is a material that permits energy to be transported in the form of heat within it, without causing the material to move. Copper and aluminium have the highest heat conductivity, while steel and bronze have the lowest.
A poor conductor or insulators of heat prevents thermal energy from passing through them. Plastics, rubber, wood, glass are few examples of poor conductor of heat