The meaning of velocity of an object can be defined as the rate of change of the object’s position with respect to a frame of reference and time.
Average velocity of a body is defined as the change in position or displacement (Δ x) divided by time interval (Δ t) in which that displacement occurs. To put it another way, it’s the rate at which an object moves from one location to another. Average velocity is a vector quantity. The SI unit is meters per second.
The instantaneous velocity is the specific rate of change of position (or displacement) with respect to time at a single point. The SI unit of instantaneous velocity is m/s. It is a vector quantity.
When average velocity and instantaneous velocity are equal?
Average velocity is equal to the instantaneous velocity when acceleration is zero.