Pneumatics uses compressed air to move things: the doors of a bus, the robots in a factory, the clamps of a workbench. Its key component is the cylinder, and this 3D simulator shows one cut open. Watch where the air comes in and goes out of a single-acting and a double-acting cylinder as the piston rod extends and retracts, and work out how much air each stroke uses. Understanding what happens inside the cylinder is the best starting point before you design pneumatic circuits with valves, and it makes the symbols in a circuit diagram much easier to remember.
