Signal
VARYING PHYSICAL QUANTITY THAT CONVEYS INFORMATION
Electrical signal; Signalling; Signaling; Weak signals; Signal (signal processing); Signalling system; Signal system; Signal systems; Signal (information theory); Signal (circuit theory); Signals; SIGNAL; Signal (electronics); Signals and systems; Electrical Signal; Signal (electrical engineering); Radio frequency signal
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers.