A revolution (from the Latin revolutio, "a turn around") is a fundamental change in power or organizational structures that takes place in a relatively short period of time. Aristotle described two types of political revolution:
1. Complete change from one constitution to another
2. Modification of an existing constitution
Revolutions have occurred through human history and vary widely in terms of methods, duration, and motivating ideology. Their results include major changes in culture, economy, and socio-political institutions.
Scholarly debates about what does and does not constitute a revolution center around several issues. Early studies of revolutions primarily analyzed events in European history from a psychological perspective, but more modern examinations include global events and incorporate perspectives from several social sciences, including sociology and political science.
Perhaps most often, the word 'revolution' is employed to denote a change in socio-political institutions