Reformism is a type of social movement that aims to bring a social or also a political system closer to the community's ideal. A reform movement is distinguished from more radical social movements such as revolutionary movements which reject those old ideals, in that the ideas are often grounded in liberalism, although they may be rooted in socialist or religious concepts. Some rely on personal transformation; others rely on small collectives, such as Mahatma Gandhi's spinning wheel and the self-sustaining village economy, as a mode of social change. Reactionary movements, which can arise against any of these, attempt to put things back the way they were before any successes the new reform movement(s) enjoyed, or to prevent any such successes.

A social movement is a loosely organized effort by a large group of people to achieve a particular goal, typically a social or political one. This may be to carry out a social change, or to resist or undo one. It is a type of group action and may involve individuals, organizations, or both. Social movements have been described as "organizational structures and strategies that may empower oppressed populations to mount effective challenges and resist the more powerful and advantaged elites". They represent a method of social change from the bottom within nations. On the other hand, some social movements do not aim to make society more egalitarian, but to maintain or amplify existing power relationships. For example, scholars have described fascism as a social movement.