A cross-chain bridge is a system that connects separate blockchains so an action on one can cause a corresponding action on another. It may support token transfers, application messages, or contract calls. The connection requires a way to verify or attest to relevant events; sharing an address format does not create interoperability by itself.
Different transfer mechanisms
In a lock-and-mint design, assets remain locked on the source chain while representative tokens are created on the destination. A return path commonly burns those representations before releasing the originals, subject to the bridge’s rules.
Other designs burn an asset on one chain and mint it on another, or use existing liquidity to deliver destination assets. These mechanisms create different custody, liquidity, and redemption dependencies. “Bridged” does not always mean the received token is the issuer’s native version.
Verification is the critical link
A bridge may rely on light-client verification, cryptographic proofs, an external signer group, or other mechanisms. Its security includes these assumptions and the security of both connected chains.
Contract bugs, compromised signers, chain reorganizations, and unavailable liquidity can disrupt transfers or expose funds to loss. Fees, finality requirements, supported token contracts, and completion times vary by route. A source-chain confirmation alone does not prove the destination action has completed.