A mechanical engineer is a professional who applies principles of engineering, physics and materials science for designing, analyzing, manufacturing, and maintaining mechanical systems. This includes machines, engines, tools or any other mechanical system that moves or transforms energy. Mechanical engineers work in various industries such as automotive, aerospace, biomedical, environmental control, robotics, and power generation among others. They use computer-aided design (CAD) software to create prototypes of their designs before building the actual product. Their main goal is to improve processes, products or systems through innovative solutions that are both cost effective and sustainable.