A measurement unit is a standard quantity that expresses a physical amount of a property. The history of mankind knows a lot of different measurement units. The earliest systems were created by the ancient people of Mesopotamia, Egypt, Indus Valley, and Persia. Today, multiple unit systems are used all over the world. Like the United States Customary System, the British Customary System, and the International System Of Units. In this project, you will learn how to convert units with bash.