Some dictionaries define an engineer as a builder of engines, and it is relatively easy to classify engineering fields using this definition. Purists will insist that modern engineers rarely dirty their hands actually building anything; however, we can, without loss of the thread being developed here, include the design of engines within the definition. For example, many electrical engineers build (design) electrical engines such as motors and generators, and automotive engineers often build internal combustion engines. We can abstract the concept of engine to include machines in general as well as complex machines such as robots and vehicles. To further the abstraction, we can include systems that transfer or convert matter or energy from one state to another under the umbrella of machine design. Examples of such systems are water treatment facilities, the domain of civil engineers, or automated manufacturing facilities that attract the attention of industrial engineers. A computer is nothing more than an information processing engine. Now the material to be processed has been taken to the highest level of abstraction, the symbolic level.

The complexity of the world we live in, with the astonishingly high rate of information exchange and shrinking global barriers, demands that engineers utilize and command information processing systems. Computers are at the core of all nonbiological information processing systems, and they process the information that they are given with strict attention to detail. The level of detail is extreme, and the process by which we specify the details of the task that we wish the computer to perform is called programming.