Signal Facts for Kids

Signal, signals or signalling may refer to:

Scientific concepts

Signal (electrical engineering), a varying quantity that can carry information over air or wires.
Signal processing, the field of techniques used to extract information from signals
Signal (computing), an event, message, or data structure transmitted between computational processes
Cell signalling (biology), the system of communication that governs basic cellular activities and coordinates cell actions
Signal (biology), electrochemical activity in an organism

Signals used in various kinds of transport:
- Road traffic signal
- Railway signal
- Semaphore
- Beacon
- International maritime signal flags, using the International Code of Signals
Signals (military), a historical name for the military communications
Signal corps, the branch of military which operates with command, control and communications systems
Signalling theory in biology, how organisms signal their state to others
Distress signal
Smoke signal (See also Category:Early telecommunications)
Signalling (telecommunications), a part of some communication protocols
Signal (recognition), a way of showing that a person recognizes something; such as the Color of the day used by police.

Any implicit, subtle, or disguised message, in situations such as:
- Partnership card games (see signal (bridge))
- Signaling (economics)
Signals and slots, a software design pattern
Kent (game) a card game also known as Signal or Kemp

In The Signal by William Powell Frith, a woman sends a signal by waving a white handkerchief.
A binary signal, also known as a logic signal, is a digital signal with two distinguishable levels
Signal transmission using electronic signals