We studied the economic systems and I don't quite understand them.
This is a traditional or subsistence economy. Here, all producers are self sufficient and only make enough produce for their needs or the needs of their family, rather than aiming to make a profit.
This is a socialist or command economy. Here, the government owns all resources and distributes them in ways that they see fit. This means that emphasis may be on areas the government want, rather than what consumers want.
This is a market or capitalist economy. Here, resources are owned privately and all decisions are made by the owners acting in self interest. Resources are used based on what consumers want and will buy.
This is a mixed economy. Here both capitalist and socialist economies are combined. There are businesses that act for a profit and government intervention in things that producers don't see as profitable. Most economies today are mixed ones.