Centralisation is when power is concentrated in one place, which could be a government, a person, or a business. Imagine that you are in a city and all the people in the city have to decide how things will work. If people decide to have centralisation, one person or group of people, like a mayor or a group of mayors, will make all the decisions for everyone. That way, everyone doesn’t have to worry about making all the decisions and can just follow the rules set by the few people in charge.