A demodulator is an electronic device that converts a modulated signal back into its original form. Modulation is the process of varying a carrier signal to transmit information, such as audio or video. Demodulators are essential in communication systems, allowing devices like radios and televisions to retrieve the information encoded in the signals they receive. Demodulators can be found in various applications, including AM and FM radio, television broadcasting, and data communication systems. They work by extracting the original message from the modulated carrier wave, enabling users to access the transmitted content effectively.