Relay architecture is a routing design that forwards traffic through one or more intermediary nodes before it reaches its destination. Each relay sees only part of the path, which makes it harder to trace the traffic back to the original source or to identify the true control endpoint.
In cyber security, this matters because attackers use relays to obscure command-and-control infrastructure, distribute load, and make takedowns more difficult. A botnet can route instructions through chained nodes, including compromised devices, so defenders must map several hops instead of finding a single server. Defenders also use relays in some contexts, but they may build sinkholes or traffic inspection points to observe or divert malicious flows. When you see unusual multi-hop connections, repeated redirects, or unexpected outbound paths from an IoT device, relay architecture may be part of the design.