Mechanical engineering is one of the oldest, broadest, and perhaps most versatile discipline among all engineering disciplines. Mechanical engineers use the principles of energy, mechanics, and materials to design and manufacture machines and devices of all types, and create the systems and processes that drive technology and virtually every industry. The key characteristics of the mechanical engineering profession are its breadth, flexibility, and individuality. Mechanical engineering derives its breadth from the need to design and manufacture everything from small individual components and devices to large engineering structures and systems. Its flexibility emanates from its scope involving materials, solid and fluid mechanics, thermodynamics, heat transfer, control, instrumentation, design, and manufacturing. Its individuality lies in the ever-emerging specialized mechanical engineering fields such as biomechanics, robotics, mechatronics, nanomechanics, microfluidics, micropower generation, MEMS and NEMS.

Mechanical engineering encompasses an understanding of core concepts including mechanics, kinematics, thermodynamics, heat transfer, materials science, structural and manufacturing analyses. Mechanical Engineers use these core concepts to conceive, design, develop, manufacture, and maintain devices and tools, equipment and machinery, products and plants that run the engineering industry. Mechanical engineers also use these core principles to ensure that the products are manufactured economically, and function safely, efficiently and reliably. Mechanical engineers work in the automotive, aerospace, chemical, computer, power, petrochemical, marine and machine tool manufacturing industries, to name a few. Thus, it may be safely stated that every product or service in the modern world has probably been touched in some way by a mechanical engineer.