What's the difference in a war and a revolution? Revolutions are usually a reaction to tyranny within a particular country. What is tyranny? Tyranny is government by an absolute ruler that often results in cruel or unjust acts against the people. A revolution involves overthrowing that cruel and unjust government and replacing it with a new government. Three of the most important revolutions in history were the American Revolution, the French Revolution and the Russian Revolution. Let's go to the Revolution Museum to learn more!