The creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct or operate the same with full cognizance of their design; or to forecast their behavior under specific operating conditions; all as respects an intended function, economics of operation and safety to life and property.
It is generally considered to consist of the major primary branches of chemical engineering, civil engineering, electrical engineering, and mechanical engineering.
There are numerous other engineering sub-disciplines and interdisciplinary subjects that may or may not be part of these major engineering branches. It consists of Computer engineering, Software engineering, Textile engineering etc.