The term technology is derived from the Greek words tékhne and lógos. Technique and technic(s) also come from tékhne. This Greek word and its Latin equivalent ars both belong to the same semantic field, referring primarily to a skill or practical process, a know-how and its products, be they objects or actions. Technology can, therefore, mean two things: i) either a scientific knowledge of tékhne or ii) a tékhne accompanied by science, that is, a know-how accompanied by a know-why. We shall normally understand technology to have this second meaning, as tékhne accompanied by or derived from science.