Socialist realism is a style of realistic art that was developed in the Soviet Union and became a dominant style in various other socialist countries. Socialist realism is characterized by the glorified depiction of communist values, such as the emancipation of the proletariat, in a realistic manner. Although related, it should not be confused with social realism, a broader type of art that realistically depicts subjects of social concern.
Socialist realism was the predominant form of art in the Soviet Union from its development in the early 1920s to its eventual fall from popularity in the late 1960s. While other countries have employed a prescribed canon of art, socialist realism in Russia persisted longer and was more restricted than elsewhere in Europe.
More information on the Wikipedia page  which includes participants, groups and examples of socialist realist art.