Exclusionary zoning is when a town or city tries to keep certain people (like people with low incomes) away by making it hard for them to find a place to live. They do this by zoning laws, which are laws that tell you what kinds of buildings can be built in different places. When a town does exclusionary zoning, it might put in rules that only allow expensive houses or that don't allow apartments at all, so that only people with a lot of money can find somewhere to live in the town. Nobody else will be able to afford to live there, so it is like the town is cutting these people out or trying to exclude them.