A social movement or popular movement is either a loosely or carefully 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.
Political science and sociology have developed a variety of theories and empirical research on social movements. For example, some research in political science highlights the relation between popular movements and the formation of new political parties as well as discussing the function of social movements in relation to agenda setting and influence on politics. Sociologists distinguish between several types of social movement examining things such as scope, type of change, method of work, range, and time frame.