In RimWorld, the Zone/Area system is a mechanic that allows players to mark a group of map tiles to serve different purposes.
Zone[]
A zone is a group of map tiles that are marked by players. Zones are used for defining which area to organize. And areas that are marked with the Zone function will have a function to control according to how they are marked. Zones can't overlap with each-other.
Stockpile Zone[]
Dumping Stockpile Zone[]
Growing Zone[]
Delete Zone[]
Area[]
An Area acts like an invisible layer that defines functions to be applied within boundaries.