Answer :

Velocity is the rate of change of the displacement, the difference between the final and initial position of the object. Speed is the rate which someone or something can move or operate.
You can think like this, Velocity is speed with a direction. When you say, the car was moving at the speed of 20 kilometers per hour, that's speed. But if you say, the car was moving at the speed of 20 kilometer per hour to the east. That's velocity, because you also stated the direction of the car.