What is meant by envelope detection?

envelop detection : is to detect the variation of the envelop of ur carierr
this type of detection is used in AM modulated signals

also it used for RF power detectors

khouly

if u multiply x(t) by cos(wt) you'll get a signal that is bounded to a signal with the same shape of x(t) that is called the envelope.to detect it you can simply use RC circuit