Signal: Meaning (information, definition, explanation, facts)

A signal may refer to:

• an abstract element of information, or, more exactly, usually a flow of information (in either one or several dimensions). See Signal (information theory).
• (in electronics) a signal is any physical phenomenon that can be modeled as a function from time or position. Signals carry information: Analog signals are continuous while digital signals are discrete (see signal processing and noise (physics)).
• a signal in computing.
• (in the streets) a means of controlling road vehicles, pedestrians or trains (see Traffic signal, Pedestrian crossing or Railway signal).
• (in a partnership card game) a player's choice of card to play at a particular time, which gives information to a partner, in a partnership card game (see signal (bridge)).