Some of the most enduring images of the Cultural Revolution come from poster arts. Propaganda art in posters was used as a campaigning tool and mass communication device and often served as the leading source of information for the people. They were produced in large number and widely disseminated, and were used by the government and Red Guards to educate the public the ideological value as defined by the party state. There were many types of posters, the two main genres being the big-character poster () and "commercial" propaganda poster ().