A machine is defined as any device that accomplishes work using mechanical or electrical energy. Machines manage energy and power to transform the magnitude and direction of force directed towards work. Increasingly insignificant to industry market and equipment demand, simple machines qualify as classical machines, but are rarely included in industry groupings. More significant machines to industry are clocks, compressors, expanders, turbo machinery, pumps (including centrifugal, positive displacement), internal and external combustion engines, reciprocating engines, other heat engines, turbines, and airfoils (wings, propellers, rudders). The advent of electronics and information technology (IT) led to the emergence of numerous devices and products without moving parts (mechanical work) that are called machines, such as devices with integrated circuitry (IC) (computers), televisions, radio, lasers and various industrial tools using electricity and electromagnetic radiation. Industrial robots and robotic arms represent a merger of machinery, electronics and information technology.
All machines are created from components or parts called machine elements, which fall into the categories of structural components and mechanisms. Structural components are things that perform primarily structural functions like frames, bearings, fasteners, springs and seals. Mechanisms are the parts of a machine that control its movements, and include gear trains and gears, linkages, and cam and follower mechanisms. Electronics and IT-enabled machines possess controller parts that maintain the performance of machine’s components using actuators, computerization, logic, and sensors.