According to the National Academy of Engineering:

"Engineering has been defined in many ways. It is often referred to as the 'application of science' because engineers take abstract ideas and build tangible products from them. Another definition is 'design under constraint,' because to 'engineer' a product means to construct it in such a way that it will do exactly what you want it to, without any unexpected consequences.

Engineers are men and women who create new products. It is estimated that there are over 2 million practicing engineers in the United States. They work in fields such as biomedicine, energy, automotive, aerospace, computers, and many others that require people to create products that didn't exist before."

National Academy of Engineering