Imperialism: This is a policy or ideology by a nation to extend its power over other areas through military force or by gaining political and economic control. It's like upgrading your property in Monopoly with houses and hotels.
Decolonization: This is the process where colonies become independent of their colonizers. Imagine if those properties you bought in Monopoly suddenly decided they didn't want to be part of your empire anymore and started operating independently.
Scramble for Africa: This term describes the rapid colonization of Africa by European powers during the late 19th century. It's like that rush in Monopoly when everyone tries to buy up all available properties on their turn.