Suppose your hands are cold and you put them under your armpits to warm them up. Heat will raise the temperature of your hands. Heat is capable of being transmitted through solids by conduction, through fluids by convection, and through empty space by radiation. It is measured in calories or Joules. To heat a substance is to do a form of microscopic work because the added heat causes the individual molecules of the substance to move more rapidly about in all directions.
Kinetic energy is energy of motion.
A car that moves faster has more kinetic energy than a car that moves slower. The atoms in a hot object move faster than atoms in a cold object. The atoms in a hot object have more kinetic energy than the atoms in a cold object. The rubber band stored the potential energy. Potential energy is the energy of position or state.