Final answer:
Communism is the state where individuals contribute based on ability and consume according to need, distinct from capitalism's market-driven approach, socialism's state-regulated distribution, and anarchy's lack of structured government.
Step-by-step explanation:
The state in which everyone contributes according to their abilities and consumes based on their needs is Communism. In a communist economic system, wealth is distributed among the citizens based on their needs, and the concept of private property is either nonexistent or greatly limited, with the state owning and controlling the means of production. This theory, in its purest form, aims to create a society where class distinctions are eliminated, and the community as a whole benefits. Capitalism, on the other hand, follows a free-market system where goods and services are distributed based on supply and demand, and prices are determined through open market competition. Socialism is an economic system where the means of production are owned or regulated by the state to some degree and wealth is distributed more evenly than in capitalism, but it allows for some measure of private ownership. Anarchy refers to a society without a publicly enforced government or a state of disorder due to absence of authority.