An apartment building is a structure with multiple individual apartment units accessed through a common entrance and hallway. It may also contain commercial spaces, such as stores, typically on the ground floor.
A common area is a portion of a property that is used and enjoyed by all owners or tenants within that property. Typical examples include clubhouses and pools in condominium developments, hallways and stairs in apartment buildings, elevators in office buildings, and the central mall area in shopping centers.
