Commerce is commerce, the buying and selling of commodities and commercial operation.
Marketing is marketing, marketing and commodity marketing, which studies the skills of selling goods.
Economie is economy, macro-economy is the international or national economic situation and operation, as well as its change, development and control, and micro-economy is the economic situation of various industries or small circles at a certain regional level.
These majors have different connotations, but many courses will be similar or the same in teaching, because each major will involve other majors. For example, the courses of finance and economics overlap, because finance is a part of economics, and economy will affect finance, and finance will also affect economy. Moreover, business and marketing will also cross. Business cannot be separated from marketing, and marketing serves business.