Velocity is a vector quantity that describes both the speed and direction of an object's motion. Here are some units in which velocity can be expressed:

Common Units:

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

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

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

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

Other Units:

* Knots: Used for nautical speeds (1 knot = 1 nautical mile per hour).

* Mach: Used for airspeed, representing the ratio of an object's speed to the speed of sound.

Important Note:

It's crucial to understand that speed is a scalar quantity that only describes the magnitude of motion (how fast something is moving), while velocity includes both magnitude and direction.