What's the difference between acceleration and constant velocity?

Acceleration is the rate at which velocity changes.

Constant velocity means zero acceleration.

Remember that both of these quantities have direction as well as size.

In other words, speed may be constant, but velocity isn't constant if the

direction of the speed changes.

Is a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocityand constant velocity means the velocity of a certain object is not changed always in the speed at which it began