In Security Center, an area entity represents a concept or a physical location (room, floor, building, site, and so on) used for grouping other entities in the system.
You can use areas to group system entities logically or to prevent unauthorized users from viewing selected system entities. A secured area is an area entity that represents a physical location where access is controlled. A secured area consists of perimeter doors (doors used to enter and exit the area) and access restrictions (rules governing the access to the area).