Hobby Aircraft is a small flying machine that is controlled remotely by an operator on the ground using a hand-held radio transmitter. The transmitter communicates with a receiver within the craft that sends signals to servomechanisms (servos) which move the control surfaces based on the position of joysticks on the transmitter. The control surfaces, in turn, affect the orientation of the plane. Flying hobby aircraft grew substantially from the 2000s with improvements in the cost, weight, performance and capabilities of motors, batteries and electronics. A wide variety of models and styles is available.