At the risk of starting another argument, I have heard it described thusly—

Suppose you have some number of apples and some number of people who want the apples.

• Capitalism is where one person owns all the apples and everyone has to work for them to get an apple.
• Socialism is where the apples are distributed evenly to all the people who want them.
• Communism is where unlimited apples fall out of the sky and everyone can have as many as they need.

Now, this quote was originally used by capitalists to mock communism, but I think it's really not a bad analogy. Think about it: Star Trek, another beloved Lemmy staple, takes place in a communist society. Everyone works whatever job they want contributing to society and in return, everyone gets whatever they need provided for by the state. It's not truly post scarcity, since human greed always outstrips any finite amount of resources. But there is no distinction of rich or poor in Star Trek. People are judged by their intelligence, skill, and merit, and rewarded proportionally. At the same time, there is no concept of money, mostly (except when the plot needs it). What good is money when all your necessities are taken care of? All but your wildest desires can be conjured up at a snap of your fingers, and all the state asks in return is that you do what you can to contribute. It is a mutually beneficial relationship that most people have learned to be content with. That, my friends, is an ideal depiction of communism.