Signals transmit or carry some type of information. A signal is anything that is visible, audible, observable or measurable with the help of some machine. Examples include speech, audio, light, radio, TV, radar, supersonic, temperature, ECG, EEG, etc.
Modulation is the process of altering a carrier signal in order to convey information. It involves superimposing the information signal onto the carrier signal, thereby changing its characteristics. There are several modulation techniques, including amplitude modulation, frequency modulation, and phase modulation. Modulation is essential for the transmission of information in various communication systems, such as radio and television broadcasting, cellular networks, and satellite communications.
Demodulation is the process of extracting the original signal from a modulated carrier wave. It is an essential step in the communication process, allowing for the transmission and reception of information. Demodulation can be achieved through various techniques such as amplitude modulation, frequency modulation, and phase modulation. By accurately demodulating the carrier wave, the original information can be recovered and interpreted.