Form follows function is more of a principle then a phrase that is used in architecture, software engineering and product design. In architecture it was used in the sense that the designs of a construction would be based on the intended use to which the constructed site would be put to use. In architecture it is often seen used along side the phrase "ornament is crime" which refers to the fact that building something as part of the design without any practical application is a waste. The two phrases as early as 1910 found usage in product design. Designers put these concepts to practical use in the manufacturing of simple things like toothbrushes, teapots, chairs etc. The phrase has found use in modern days in software engineering where it is seen applied to modern businesses' Enterprise Application Architectures.
