Relay (disambiguation)

A relay is an electric switch operated by a signal in one circuit to control another circuit.

Relay may also refer to:

Electrical engineering

• Protective relay, a device designed to trip a circuit breaker when a fault is detected.

Historical

• Stage station, a place where exhausted horses being used for transport could be exchanged for fresh ones
• Cursus publicus, a courier service in the Roman Empire
• Relay league, a chain of message-forwarding stations

Computer networking

• BITNET Relay, a 1980s online chat system
• Mail relay, a server used for forwarding e-mail
  • Open mail relay, such a server that can be used by anyone

Other telecommunication

• Relay (satellite)
• Broadcast relay station, a transmitter which repeats or transponds the signal of another
• Microwave radio relay
• Relay channel, in information theory, a communications probability modeling system
• Telecommunications Relay Service, a telephone accessibility service for the deaf
• Repeater, an electronic device that receives and retransmits a signal

See also: ARRL

Automobiles

• Citroën Relay, a marketing name for the Fiat Ducato van
• Saturn Relay, a 2005-2007 minivan

Other uses

• Relay (shop), a France-based chain of convenience stores
• Relay (company), a peer-to-peer political texting platform
• Relay (film), a 2024 thriller film
• "Relay" (song), 1972, by The Who
• Relay bid, in contract bridge
• Relay race, completed in parts by several participants of a team
• Relay neuron, in anatomy
• Relay box, a piece of postal infrastructure.
• Relay (podcast network)

See also

• Retransmission (disambiguation)
• Relais