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

Relay may also refer to:

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

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" (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

See also

• Retransmission (disambiguation)

Disambiguation page providing links to topics that could be referred to by the same search term This disambiguation page lists articles associated with the title Relay. If an internal link led you here, you may wish to change the link to point directly to the intended article.