Electricity differs from air, steam, or water in that it does not actually convey heat from one point to another; therefore, including it in a list of heat-conveying mediums can be misleading at first glance.
Electricity can best be defined as a quantity of electrons either in motion or in a state of rest. When these electrons are at rest, they are referred to as being static (hence the term static electricity). Electrons in motion move from one atom to another, creating an electrical current and thereby a medium for conveying energy from one point to another. Many different devices have been created to change the energy conveyed by an electric current into heat, light, and other forms of energy. Electric-fired furnaces and boilers are examples of devices used to produce heat.