THE AMA HANDBOOK OF BUSINESS WRITING

Trade exchanges of wealth, goods, services, knowledge, money, etc. between two or more partners, and can get a certain value (in cash through price) or bygoods and services, such as in the form of barter trade (barter). In this process, the seller is the provision of goods, commodities, services ... to the buyer, in exchange for the buyer will pay the seller a certain equivalent value.