Transmitters and recievers are the two pieces of electronics that keep you in control of your plane. They both have omni directional antennas so as the planes orientation changes as it flies around you the two antennas signals remain in contact with each other. Many transmitters have an antenna that has a hinge in it, thats because the signal emitted has a big dead holedown the length of the antenna so if you have your antenna pointing at your aircraft you will eventually lose connection with your aircraft(look at this video to understand why)
