A cross-chain bridge is a chain-to-chain connection that allows the transfer of tokens and assets from one chain to another. Cross-chain bridges can facilitate communication and trade by making the two chains compatible with one another. According to statistics from DeFi Llama, the total value locked in DeFi on Etherum had exceeded $161.5 billion as of October 22, 2021. The total value of TVLance Bridges, Polygon Bridges, Arbitrum Bridges, Optimism Bridges, etc – had reached approximately $25 billion.