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. The demodulator extracts this information from the modulated signal, making it usable for devices like radios and televisions. Demodulators are essential in communication systems, enabling the reception of signals over long distances. They work in conjunction with modulators, which perform the opposite function by encoding information onto a carrier signal. Common types of demodulation include amplitude modulation (AM) and frequency modulation (FM).