First coined by the American architect, Louis Sullivan, at the end of the nineteenth century, the phrase "form follows function" has become a mantra for many product designers. The basic meaning of the phrase is that the appearance, shape, and method of use of the object (the form) should naturally be derived from the intended purpose (function) of the object. Thus, a chair should look like, work like, and feel like something a person is to sit in.
Sadly, this phrase has been misquoted, abused, and misunderstood in many different ways. Some mistakenly believe that "form follows function" means one should engineer a product, then wrap a form around it; in the sense of this phrase, however, engineering is a part of 'form'. The product should be both engineered and designed to fit the specific function it is intended to fulfill.