Wormhole has a Core Bridge contract deployed on all the connected networks. Wormhole Guardians run a full node for each of the connected chains, specifically listening to any events from the Core Contracts. The core contracts emit a message, which is picked up by the Guardians. The Guardians verify the message and sign it, creating a VAA (Verified Action Approval). This VAA then sits on the Guardians network where it can be retrieved by the user or by a relayer to be submitted to the target chain to process the message. Unlike other bridges, a relayer in Wormhole has no special privileges, it’s just a piece of software that shuttles messages between the Guardian network to the target chain, and is not a trusted entity.