* Meters per second (m/s): This is the standard unit in the International System of Units (SI).

* Kilometers per hour (km/h): Commonly used for road speeds.

* Miles per hour (mph): Used in the United States and some other countries.

* Feet per second (ft/s): Used in some engineering applications.

* Knots (kt): Used for maritime and aviation speeds.

Remember, velocity is a vector quantity, meaning it has both magnitude (speed) and direction. So, a complete description of velocity requires both a unit of speed and a direction.