A cross-chain bridge allows you to launch your token on multiple blockchains. The bridge is essentially a smart contract that we deploy on 2 or more chains and facilitates the movement of tokens between the blockchains. When a user wants to send tokens from one blockchain to another, they can connect to the bridge through the web application with their web3 wallet. The tokens are locked inside a smart contract and the corresponding number of tokens are minted on the other blockchain. When the opposite happens, the newly minted tokens are burned and the smart contract on the first blockchain unlocks the tokens. In case both tokens have the mint functionality, this process can happen without token locking through minting and burning alone.
https://www.blockchainx.tech/bridge-smart-contract-development