Rate of change of displacement with respect to the time is called velocity.

The velocity \(\vec{v}\) of a particle is given by the following formula,
$$ \vec{v} = \frac{\vec{x}}{t}$$
\(\vec{x}\) = displacement of a particle
t = time taken

Velocity is a vector quantity. SI unit of velocity is metre/second and its dimensional formula is [ M0L 1T-1 ].