Terror, is from the French terreur, from Latin terror meaning "great fear", a noun derived from the Latin verb meaning "to frighten", is a policy of political repression and violence intended to subdue political opposition. The term was first used for the Reign of Terror during the French Revolution. Modern instances of terror include or .
Before the late twentieth century, the term "terrorism" in the English language was often used interchangeably with "terror." Some contemporary writers use terrorism to refer to acts by groups with a limited political base or parties on the weaker side in asymmetric warfare and terror to acts by governments and law enforcement officials, usually within the legal framework of the state. Others consider state terror to be a specific type of terrorism.
Revolutionary terror, also known as "Red terror", was often used by revolutionary governments to suppress counterrevolutionaries. The first example was the Reign of Terror during the French Revolution in 1794. Other notable examples include the Red Terror in Soviet Russia in 1918–1922, as well as simultaneous campaigns in the Hungarian Soviet Republic and in Finland. In China Red Terror in 1966 and 1967 started the Cultural revolution.