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.
A direct measurement is when you take it against an international standard (a meter for example), while an indirect measurement is when you measure something against something that isn't standard (she must be 5'11 because he's 6'2 and just a bit taller.)