Signal

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

Communications

• 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.

Names

• Signal band A rock band from Northwest Indiana
• Signal (band), a Bulgarian rock band
• Signals (album), an album by progressive rock band Rush
• Signal (magazine)
• Signal (toothpaste)
• Signal 1 and Signal 2 radio stations
• Signal (subscription service), service that provided real-time stock quotes
• Signaal (now Thales Nederland), a Netherlands-based defence company
• Signal Systems, a company of the McLean Group of Companies

Other

• 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