What defines a pneumatic system?

A pneumatic system is specifically defined as a system that utilizes compressed air to perform work. Pneumatic systems operate on the principles of compressible fluids, where compressed air acts as the medium to transmit energy and force. This characteristic allows for the control of various tools and machinery by converting the energy from compressed air into mechanical motion.

The fundamental operation involves pressure differentials created by the compressed air, which can move cylinders, actuators, and other components to accomplish tasks such as lifting, pushing, or rotating. The use of air in this manner provides several advantages, such as lighter equipment, less risk of fluid leaks compared to hydraulic systems, and the ability to perform a wide range of tasks in diverse environments.

The other choices refer to different types of systems that operate based on various principles: hydraulic systems rely on incompressible fluids, electrical systems convert electrical energy into mechanical work, and gear-based systems are mechanical systems that use interlocking gears for motion. These distinctions highlight why the correct answer specifically revolves around the use of compressed air in pneumatic systems.