Architecture is the art and science of designing the built environment; including cities, buildings, interiors, landscapes, furniture, objects and so on. Previously the term was architecture more used now mainly for the aesthetic use side of the building, while engineering is used in particular for the technical side. A certain practitioner of architecture is called an architect .
According to the earliest surviving work on the subject, ” On Architecture ” of the Roman Vitruvius , architecture is based on three principles: Beauty ( venustas ), firmness ( firmitas ) and usability ( utilitas ). They can then be defined as the balance between these three elements, in which none of the three is so predominant with respect to the other two.