The two measurement systems generally in use are the English System and the Metric System.
Metrification is important because nearly all world trade involves metric goods.
Presently, the US is out of step with the rest of the world. This compromises our international competitiveness and limits markets for American-made products. No, not England, not France, not Canada, not Mexico. If you guessed any countries other than Liberia and South Yemen, you would be wrong. Many cars are already built with speedometers in both miles per hour and kilometers per hour.