Architecture is both the process and the product of planning, designing, and constructing buildings or any other structures. Architectural works, in the material form of buildings, are often perceived as cultural symbols and as works of art. Historical civilizations are often identified with their surviving architectural achievements.  

While the notion that structural and aesthetic considerations should be entirely subject to functionality was met with both popularity and skepticism, it had the effect of introducing the concept of "function" in place of Vitruvius' "utility". "Function" came to be seen as encompassing all criteria of the use, perception and enjoyment of a building, not only practical but also aesthetic, psychological and cultural.  

The architecture and urbanism of the Classical civilizations such as the Greek and the Roman evolved from civic ideals rather than religious or empirical ones and new building types emerged. Architectural "style" developed in the form of the Classical orders. Roman architecture was influenced by Greek architecture as they incorporated many Greek elements into their building practices.  

The architecture of different parts of Asia developed along different lines from that of Europe; Buddhist, Hindu and Sikh architecture each having different characteristics. Buddhist architecture, in particular, showed great regional diversity. Hindu temple architecture, which developed around the 3rd century BCE, is governed by concepts laid down in the Shastras, and is concerned with expressing the macrocosm and the microcosm. In many Asian countries, pantheistic religion led to architectural forms that were designed specifically to enhance the natural landscape.  

The Late Middle Ages in Central and Southeastern Europe also saw the expansion of Ottoman architecture, which spread alongside the Ottoman Empire, from Anatolia via the Balkans, to Central and Eastern Europe and beyond to the northern shores of the Black Sea. In regions from which the Ottoman Empire would eventually be forced to retreat, almost all their architectural designs were destroyed. In the 21st century, the only significant architectural heritage on European soil outside of modern-day Turkey, can be found in Bosnia and Herzegovina, Kosovo, and Albania, while some remnants can be found in the Muslim-inhabited parts of Serbia, Montenegro, Macedonia and Bulgaria.  

With the emerging knowledge in scientific fields and the rise of new materials and technology, architecture and engineering began to separate, and the architect began to concentrate on aesthetics and the humanist aspects, often at the expense of technical aspects of building design. There was also the rise of the "gentleman architect" who usually dealt with wealthy clients and concentrated predominantly on visual qualities derived usually from historical prototypes, typified by the many country houses of Great Britain that were created in the Neo Gothic or Scottish Baronial styles. Formal architectural training in the 19th century, for example at Ecole des Beaux-Arts in France, gave much emphasis to the production of beautiful drawings and little to context and feasibility.  

When modern architecture was first practiced, it was an avant-garde movement with moral, philosophical, and aesthetic underpinnings. Immediately after World War I, pioneering modernist architects sought to develop a completely new style appropriate for a new post-war social and economic order, focused on meeting the needs of the middle and working classes. They rejected the architectural practice of the academic refinement of historical styles which served the rapidly declining aristocratic order. The approach of the Modernist architects was to reduce buildings to pure forms, removing historical references and ornament in favor of functionalist details. Buildings displayed their functional and structural elements, exposing steel beams and concrete surfaces instead of hiding them behind decorative forms. Architects such as Frank Lloyd Wright developed organic architecture, in which the form was defined by its environment and purpose, with an aim to promote harmony between human habitation and the natural world with prime examples being Robie House and Fallingwater.