Chain architecture

Native token structure
Ethereum is a blockchain, so its native token ETH is built into the protocol. That's why it doesn't have a contract address on its own blockchain.
Consensus mechanisms
Proof of Stake (PoS)

Since September 15, 2022, Ethereum transitioned from Proof of Work (PoW) to Proof of Stake (PoS) with a major protocol update known as The Merge.