A receiver is any electronic device that receives an external signal (e.g., radio, electrical or optical) and converts the information carried by them to a usable internal form.
In communications, a receiver is any electronic device that converts a signal that has been transmitted a long distance (e.g., radio waves, optical pulses or even baseband signals on a cable) and converts the information carried by it to a usable form. This process may include rejection of unwanted signals, demodulation and/or amplification.
