Source: Oxford University Press
A small-scale three-dimensional structure used to test, clarify or illustrate part or all of an architectural design or building. Although frequent references to the use of models can be found from Classical antiquity onwards, because of their often fragile materials (e.g. wood, gesso, papier-mâché and balsa wood), few have survived in proportion to their extensive use. Those that remain date chiefly from the end of the 15th century, or shortly after, and tend to represent monumental rather than intimately scaled buildings. Moreover, documentary references from the Renaissance, when a fresh interest in the use of models emerged, are sometimes misleading. The term ‘model’, derived from the Italian modello, frequently refers to a drawing rather than a three-dimensional aid for the designer. With the advent of a wide range of specialized drawings in the late 18th century, the value of the model as a presentational and didactic device was first seriously undermined. Nevertheless, it continued to prove useful up to the late 20th century, when holography and sophisticated computer graphics began to replace it as a source of three-dimensional information for architects and clients.
From Grove Art Online