Mercantilism: Mercantilism is an economic system where colonies existed solely for the benefit of the mother country by providing raw materials and serving as markets for finished goods.
Imperialism: Imperialism is a policy or ideology of extending a nation's authority by territorial acquisition or by establishing economic and political dominance over other nations.
Decolonization: Decolonization refers to the process by which colonies gained independence from their colonizers, often leading to the establishment of new nation-states.