An apartment, flat, or unit is a self-contained housing unit that occupies part of a building, generally on a single storey. There are many names for these overall buildings. The housing tenure of apartments also varies considerably, from large-scale public housing, to owner occupancy within what is legally a condominium, to tenants renting from a private landlord.

Real estate is property consisting of land and the buildings on it, along with its natural resources such as growing crops, minerals or water, and wild animals; immovable property of this nature; an interest vested in this (also) an item of real property, buildings or housing in general. In terms of law, real relates to land property and is different from personal property while estate means the "interest" a person has in that land property.