velocity tells us not only the speed of a body but also the direction along which the body is moving. It is equal to the displacement of a body in unit time.
The rate of displacement of a body is called its velocity.Velocity is a vector quantity.
SI unit of the velocity is m/s.
In many cases the speed and direction of a body does not change. we can say, the body possesses uniform velocity. That is the velocity of a body during any interval of time has the same magnitude and direction.
A body has uniform velocity if it covers equal displacement in equal intervals of time however short the interval may be.
In some cases the speed and direction of a body changes. we can say, the body possesses variable velocity.
A body has variable velocity if it covers unequal displacement in unequal intervals of time however short the interval may be.