What is Communism?
Communism is a stateless, classless, moneyless society. In it, no one is exploited for his labor or treated any different because of where he’s from, who he was born to, or what job he does. Everyone simply works to provide society what he is able to, and in turn receives all that he needs without any personal “exchange” of goods or services.
The communist economic system was summarized by Karl Marx as:
From each according to his ability, to each according to his needs!
In modern vernacular, this is often called “socialism”, where the means of production are not owned by any one person or persons, but where society as a whole owns everything which produces products.