Displacement current is defined as the limited shifting of electric components that takes place within a dielectric when a voltage is applied or removed from it (as in charging or discharging a capacitor) and that corresponds to the current in the circuit supplying the voltage.
Displacement current is needed as:
It is required to make the conduction current to lead in the circuit. For example when a current flows through an inductor, it lags behind the voltage, but by using a capacitor in a circuit, conduction current in wires can be made to lead the voltage by means of displacement current inside the capacitor and it has vast uses in induction motors, industrial appliances and in our day to day life.
