Velocity is defined as the rate of change of displacement with time. It is a vector quantity and has units m/s. The direction of a velocity vector is same as the direction of the motion of body at that instant of time. Magnitude of instantaneous velocity is same as the speed at the instant.
Average Velocity=Total timeTotal Displacement It is a vector quantity and has units of m/s. Magnitude of average velocity is always less than or equal to the average speed because displacement is always smaller than or equal to distance.