Kilometers per hour (kph, km/h)
Kilometers per hour (kph or km/h) is a unit of speed. Kph is a unit commonly used to express the speed of vehicles, such as cars and trains.
Kilometers per second (km/s)
Kilometers per second (km/s) is a unit of speed that measures the number of kilometers traveled in one second. It is occasionally used in astronomy and astrophysics where large distances are involved.