重要的是要认识到，尤其是在历史上，工程师和工程专业的工作与科学家的工作是不同的。“应用科学”一词并没有完全涵盖这项工作，因为工程师一直被要求设计科学尚未完全理解的产品。由于工程在一些国家既是一种行业，也是一种职业，“技术”一词经常与工程互换使用，因此定义问题变得更加复杂。引文:德克萨斯州休斯顿ASHRAE学报第88卷第1部分研讨会

It is important to recognize, particularly when speaking historically, that the work of the engineer and of the profession of engineering is not the same as the work of the scientist. Not is the work fully covered by the term "Applied Science" since the engineer has been, and still is, called upon to design products for which the science is not fully understood. And matters of definition are further complicated by the fact that engineering in some countries is a trade as well as a profession, and also the term 'technology, is often used interchangeably with engineering.