The Wealth of Nations by Part 2 Chapter 5 Page 26

consumption, and the carrying trade. The home trade is employed in purchasing in one part of the same country, and selling in another, the produce of the industry of that country. It comprehends both the inland and the coasting trade. The foreign trade of consumption is employed in purchasing foreign goods for home consumption. The carrying trade is employed in transacting the commerce of foreign countries, or in carrying the surplus produce of one to another.

The capital which is employed in purchasing in one part of the country in order to sell in another the produce of the industry of that country, generally replaces by every such operation two distinct capitals that had both been employed in the agriculture or manufactures of that country, and thereby enables them to continue that employment.