Capitalism, Communism, and a Mixed Economy

What's the difference between capitalism, communism, and a mixed economy?

In capitalism, if a CEO like Roger Smith bets the company on a new technology and loses, losses are limited to the money invested by preexisting shareholders and creditors.

In communism, if a commissar bets the kolkhoz on a new type of whip and loses, every soviet citizen is on the hook for the losses until the next purge, when the commissar gets executed.

In a mixed economy, if a CEO like Roger Smith bets the company on a new technology and loses, every taxpayer is on the hook for the losses indefinitely.