Step 1: Definition:
A social movement is an organised, sustained collective effort by a group of people to bring about, or resist, social, political or cultural change, involving shared ideology, some leadership and a degree of formal organisation over time, unlike a spontaneous, unorganised crowd action.
Step 2: Reformative movements:
Reformative movements seek partial change within the existing social system rather than overturning it entirely, for example the Bhoodan movement, which sought voluntary land redistribution to landless peasants.
Step 3: Revolutionary/transformative movements:
Revolutionary movements seek fundamental, total change of the existing social order, aiming to replace the entire political-economic system rather than reform parts of it.
Step 4: Redemptive/expressive movements:
Redemptive or expressive movements focus on transforming individuals themselves, often through religious or spiritual means, rather than aiming directly at changing the wider social structure.
Step 5: Issue-based movements:
Movements are also commonly classified by their specific focus, such as peasant movements, tribal movements, women's movements, environmental movements, and identity-based caste, ethnic or regional movements, each organised around the particular grievances of the group involved.
Final Answer:
A social movement is an organised, sustained collective effort for (or against) change; its main types are reformative (partial change), revolutionary (total change), redemptive (individual transformation), and various issue-based movements such as peasant, tribal, women's and environmental movements.