How they work
Native bridges are run by the network itself; third party bridges use validators, liquidity pools or messaging protocols to confirm transfers. Some swap the token for a native one on arrival, others hand you a wrapped version.
Why they get hacked
A bridge holds large pools of locked tokens, so a flaw in its code or a compromise of its signers can be catastrophic. Bridge hacks such as Ronin and Wormhole are among the largest thefts in crypto history.