A person who comes up with an idea for a better service or product is an entrepreneur. He'll sell them for money. Goods are tangible products that are used by consumers or producers. Consumer goods are used by consumers. Producer goods are goods used in production.
Interdependence occurs when people depend on one another.
Specialization brings about interdependence. The United States makes cars and sends cars to China. Taxes are the money the government collects from individuals and businesses to pay for public goods and services. This man dislikes paying his taxes. Money is a medium of exchange which makes trade easier.