This is the process of adding information (music, data, etc) to a carrier signal.
The carrier can be
- a radio wave
- a beam of light
- a beam of infra red
- one or more high frequencies in a cable
The modulation can be analogue
- AM (amplitude modulation)
- FM (frequency modulation)
The modulation can be digital
- PAM (pulse amplitude modulation)
- PWM (pulse width modulation)
- PPM (pulse position modulation)
- PCM (pulse code modulation)
