Adding to this: Communism exists ubiquitously in the workplace amongst the workers. No one asks their coworkers for pay for assistance, etc.. People work very effectively in teams. The same applies in families. Duties and responsibilities are assigned by ability, and need. In reality, communism is working efficiently everywhere we look. It is as old as society.

Violence of capitalism is also everywhere we look. Workplace deaths and injuries. Generally, because the owner classes cut corners on safety, and safety related regulation.

The public doesn't often hear about this violence, because the media is also run by the owner class.

This violence is the reality for most people in so-called capitalist societies.

Don't believe the propaganda.

Edit: I don't think that Marx defined communism, or how it would work. Please correct me if I'm mistaken.