Radio transmitter and receiver

What the transmitter does is it sends a signal to the receiver. The receiver receives this signal and does according to the command from the transmitter. Since the drone floats in the sky, it needs to send signals to command the drone to move or do something. So we need the transmitter and receiver. There are lots of transmitters and receivers out there. The transmitter looks like a remote, which is controlled by the drone pilot and the receiver is connected to the flight controller. So, if the pilot gives commands from the transmitter to the drone, the drone receives it via the receiver and the flight controller processes the signal and does, as per the command of the pilot.