Introducing the bridge technology

Validators earn the ETH currency as a reward when validating transactions on the Ethereum mainnet. So, does that mean ETH does not exist on L2s such as Arbitrum, Optimism, Starknet, and so on? ETH does exist on L2s. ETH are not created from validators of transactions on L2s. ETH on L2 comes from ETH on the Ethereum mainnet. So, how do you send ETH from the Ethereum mainnet to an L2?

Bridging ETH

Basically, an L2 blockchain has smart contracts that live on the Ethereum mainnet that act as a gateway or connector between the Ethereum mainnet and L2. The way it works is simple. On the Ethereum mainnet, you send X amount of ETH to a smart contract called Y. Then, X amount of ETH will be born on the L2. The amount of ETH on the L2 blockchain tallies with the amount of ETH that the Y smart contract on the Ethereum mainnet holds.

But to whom does this ETH belong? It’s up to the rules you define in the smart contract. You can create a map variable...