Drifting motion of electron is current. We can say flow of electron is current. Practically electron does not flow inside the metal rather oscillate and called as drifting motion. With the application of voltage, this drifting motion creates which helps to transfer energy. With the drifting motion, energy transform to another place which creates motion of electric device, heating etc.
The flow of electron/flow of energy get refusal due to collide with the ions in the metal. This is an irritating situation for current to flow and the property of refusal is called resistance.
We can express this resistance using Ohm’s Law: R = V / I. The SI unit of resistance is Ohm.