Community Medicine has been defined as ‘a branch of medical practice that is concern with promoting, maintaining, and when necessary, restoring the health of human communities, rather than with clinical care of individual patients. In general, it is practiced in relation to populations having defined health care facilities.
Social medicine stands upon two pillars, Medicine and Sociology. Social Medicine, by derivation is concerned with the health of groups of individuals and individuals within these groups with a view to create, promote, preserve, and maintained optimum health.
You will find that the term like Preventive Medicine, Social Medicine and Community Medicine are being used interchangeably in practice, in the textbooks and in the conversation of intelligentia.