What makes a revolution a revolution?
In all revolutions, something is changed in society. In the French Revolution,for example, the French removed their monarch and instead set up various forms of republics. Within the one revolution, the type of government changed a number of times. However, during the overarching revolution, the society changed from never questioning their sovereign ruler, to feeling that it was right to kill him. They began questioning who had authority and what they did with the power. This change in how society thought was so completely different from where it started. It turned in a complete circle.
A revolution does not even have to be where people overthrow a government. During the Enlightenment, no rulers were explicitly overthrown, but people merely started questioning where their knowledge came from and whether or not it was valid. People refer to the Enlightenment as a revolution, and thus a revolution can be considered something where the culture of a society changes, the way people act and think, and not the government.