The characteristics that distinguish a work of architecture from other built structures are
(1) the suitability of the work to use by human beings in general and the adaptability of it to particular human activities,
(2) the stability and permanence of the work’s construction, and
(3) the communication of experience and ideas through its form.
All these conditions must be met in architecture. The second is a constant, while the first and third vary in relative importance according to the social function of buildings. If the function is chiefly utilitarian, as in a factory, communication is of less importance. If the function is chiefly expressive, as in a monumental tomb, utility is a minor concern. In some buildings, such as churches and city halls, utility and communication may be of equal importance.
The present article treats primarily the forms, elements, methods, and theory of architecture. For the history of architecture in antiquity, see the sections on ancient Greece and Rome in Western architecture; as well as Anatolian art and architecture; Arabian art and architecture; Egyptian art and architecture; Iranian art and architecture; Mesopotamian art and architecture; and Syro-Palestinian art and architecture. For later historical and regional treatments of architecture, see African architecture; Chinese architecture; Japanese architecture; Korean architecture; Oceanic art and architecture; Western architecture; Central Asian arts; Islamic arts; South Asian arts; and Southeast Asian arts. For a discussion of the place of architecture and architectural theory in the realm of the arts, see aesthetics. For related forms of artistic expression, see city; interior design; and urban planning.