Relay node definition
In networking, a relay node is a component that serves as an intermediary for transmitting data between different parts of a network. Relay nodes receive data from one source and then forward it along (thus “relaying” the information across the network).
Relay nodes in networking should not be confused with relay nodes in blockchains (such as the relay nodes used in Bitcoin’s Lightning Network), which temporarily manage and relay transactions outside of the main chain.
How relay nodes work
The relay node acts as an intermediary station that temporarily holds and forwards data packets. It receives data from the source and passes it along to the next. Data relays can involve multiple hops, with data passing through multiple relay nodes before reaching its final destination.
Main relay node uses
Relay nodes are used when direct communications between the source and the destination are not feasible for some reason — for example, because the distance between the two devices is too great or the network is congested. As a result, relay nodes are commonly used in mesh networks and ad hoc networks, where direct communication between all nodes is impractical.
In a wireless network, relay nodes can also extend the coverage area — for example, cellular networks can place relay nodes strategically to enhance signal strength in areas with weak reception.
Finally, relay nodes can enhance user security and privacy by acting as proxies. In this case, the node masks the identity and location of the original sender.