A modulator is a device or component that alters a signal to encode information. It is commonly used in communication systems to modify a carrier wave, which can be a radio frequency signal, by varying its amplitude, frequency, or phase. This process allows the transmission of data over long distances, making it essential for technologies like radio, television, and cellular networks. In addition to communication, modulators are also used in audio and video processing. For example, in music production, a modulator can change the sound wave characteristics to create effects like vibrato or tremolo. This versatility makes modulators important in both technical and creative fields.