Collective behavior involves large groups acting together in an unplanned manner and can take various forms such as crowds, mass behavior, social movements, and social change. Crowds are temporary gatherings that share a focus and can become suggestible, while dispersed collectives like mass behavior involve people spread over a wide area sharing common information sources. Social movements aim to promote or resist social change through organized collective action. Theories of social movements examine factors like deprivation, resources, and the social construction of issues. Frame analysis explores how social movements define problems, solutions, and motivations to mobilize participants.