The Quadcopter (Quad) is also called Quadrocopter, Quadricopter, Quad Rotor or Drone. They all belong to the multi rotors  RC  category.   A  Quad  have four propellers arranged in across type configuration. The propellers are fixed pitch, two will spin clockwise and the other two will spin counter clockwise. By precisely spinning these four propellers at different speeds, the aircraft is able to take off vertically, hover and fly in all directions. The Quads are very simple when compared to RC helicopters. All that is needed is a frame, motors, the ESC’s (Electronic Speed Controller), propellers, the receiver-transmitter, an electronic stabilization system and a Li-Po battery.