The law of conservation of energy states that energy can neither be created nor be destroyed, but it can be transformed from one form to another.
So I considered an example of it as follows: water is stored at height with potential energy, the water flows and its potential energy is converted into kinetic energy. It flows to rotate a turbine with mechanical energy. Then the kinetic energy is converted into electrical energy. In our house the electrical energy is converted into luminous energy, heat energy, and so on.
