Pneumatic actuators, air cylinders, and air motors are used to convert compressed air into mechanical power. As compressed air is introduced to each of these devices, the air either expands or pushes forward to engage with the mechanism, powering it to create motion. Pneumatic actuators use pistons and seals to create rotary motion. Air cylinders use pistons and pressure to create linear motion, while air motors use expansion of compressed air to create linear or rotary motion.