Miles per hour (mph, mi/h)
Miles per hour (mph or mi/h) is a unit of speed. Mph is a unit commonly used to express the speed of vehicles, such as cars and trains in countries that have traditionally used the imperial system such as the United States and United Kingdom.
Knots
A Knot is a unit to measure speed. A knot is equal to one nautical mile per hour. Normally this unit is used in maritime and aviation.