When the current in a coil changes, an induced voltage appears in that same coil. This is called self-induction. The voltage (electromagnetic force) induced is called self-induced emf. It obeys Faraday’s law of induction as do any other induced emf’s. For a closed- packed coil (an inductor) we have
In summary, an inductor stores energy in a magnetic field, and the capacitor stores energy in an electric field.