If business is now a global affair, then the export-import business is important, lucrative and necessary. An export-import agent is not a broker --- the agents are lower on the business totem pole.
Most properties are measured using a number and a unit of measurement. The unit of measurement is a standard amount. The number compares the property to that standard amount. This means a tree that is ten times as tall as a meter stick is 10 meters tall.
Measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind. The definition, agreement, and practical use of units of measurement have played a crucial role in human endeavour from early ages up to the present. A multitude of systems of units used to be very common.