The word "紫禁城" is formed by combining three characters: "紫" meaning purple, which historically references the North Star as the celestial emperor's abode; "禁" meaning forbidden, indicating restricted access; and "城" meaning city or walled enclosure. Together, they literally denote the "Purple Forbidden City", reflecting its role as the imperial palace where the emperor, aligned with cosmic authority, resided in a secluded area off-limits to the public.