An object is said to have uniform velocity if the direction of motion and the rate at which the object changes its position is constant. In other words, an object with uniform velocity continues to cover the same amount of distance over the same time interval without changing its direction.

Velocity is a vector quantity. These quantities, which include velocity and acceleration, are defined by both their magnitude and their direction. For this reason, a change in velocity can occur either through a change in the magnitude of the velocity or a change in the direction that the object is traveling or both. Since velocity is also defined by its direction, having a constant speed is not sufficient for an object to have uniform velocity. If the object changes direction while it is maintaining its speed, it is considered to have non-uniform velocity. For velocity to be uniform, or constant, its magnitude and direction must remain constant. The magnitude of velocity remains constant as long as an object covers equal amount of distance in equal intervals of time. The magnitude of velocity is also called speed. Speed is a scalar quantity, which is a quantity that is defined by magnitude alone.