When you think about revolutions, you probably think "war" and "overthrowing a government", right? Although that is true, the Merriam-Webster dictionary lists many definitions for revolution, only one of which pertains to war; "A fundamental change in political organization especially the overthrow or renunciation of one government or ruler and the substitution of another by the governed". Basically what this says is that the people of a country go to war with their own government in order to make a whole new government based on what the people want. While the majority of the revolutions you have heard of most likely included wars, Merriam-Webster lists another definition for revolution; "A fundamental change in the way of thinking about or visualizing something". This means that there is a widespread change in how people think, so this type of revolution is generally peaceful. Since the most well-known revolutions are indeed violent, sometimes people don't realize how many peaceful revolutions have actually happened. As you can see in the infograph below, since 1979 there have actually been more peaceful revolutions than non-peaceful ones.