Kilometer per hour is a measure of speed, typically used in countries that use the metric system. In these countries, road speed limits are calculated in kilometers per hour, which is abbreviated as kph or km/h. As its name implies, this unit represents the distance (in kilometers) traveled by an object for one hour. This measure is usually an average, that is, if a car traveled the distance of 210 km between two cities and to take this route, it took an hour and a half, so we will get a speed of 140 kilometers per hour (140 km/h). This does not obviously mean that the car has constantly shifted at this speed, there may be parts of the route on which it has been faster and parts where it has circulated more slowly.
Mile per Hour is a unit of measure used in the United Kingdom and the United States to express speed in terms of the number of ground miles traveled for one hour. The acronym used to abbreviate mile per hour is mph. It should be noted that there are several types of miles (such as the land mile or the sea mile), so the conversion of speeds specified in miles per hour depends on the context in which it is inserted. Several English-speaking countries use this speed measure to set boundaries on roads. Interestingly, Canada is one of the few countries in the world, at which train speed is measured in miles per hour, but the speed of the cars on the roads is measured in kilometers per hour.