What is Bridge?
A bridge moves assets or messages between blockchains, usually by locking on one side and issuing a representation on the other. Bridges have been the single largest source of losses in Web3.
In practice
The risk is structural: a bridge holds pooled collateral and depends on whoever attests that the other side is valid. Trust-minimised designs use light clients or proofs; faster designs use a validator set or multisig you must trust. Always check what backs the wrapped asset you receive.