Here's why:

* Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.

* Magnitude is measured in units of distance per unit of time.

* Meters (m) is a common unit for distance.

* Seconds (s) is a common unit for time.

Therefore, the most common and standard unit for velocity is meters per second (m/s).

Other units for velocity include:

* Kilometers per hour (km/h)

* Miles per hour (mph)

* Feet per second (ft/s)

The specific unit used depends on the context and the desired level of precision.