When you look under the hood, bridges like Ronin's typically work by locking cryptocurrency into smart contracts on a chain and then re-issuing those tokens in "encapsulated" form on a destination chain. So, for example, if you were to use the Ronin Bridge to move Ether (ETH) from Ethereum to Ronin, ETH would be locked up on Ethereum to act as a 1:1 backing for Wrapped Ether (WETH) issued on Ronin.