Ethereum

Ethereum is a programmable blockchain proposed by Vitalik Buterin in a white paper published in late 2013 and launched on 30 July 2015. Its native currency is ether (ETH), which pays for transaction fees, known as gas, and secures the network through staking.

Where Bitcoin is focused on being money, Ethereum was designed to run smart contracts: programs that execute automatically on the blockchain. These power most of DeFi, NFTs, stablecoins such as USDT and USDC (which also run on other chains), DAOs and thousands of other tokens built on its ERC-20 standard.

Ethereum switched from proof of work to proof of stake in "the Merge" on 15 September 2022, cutting its energy use by more than 99.9%. Since 2021 part of every fee is burned, so ETH has no fixed supply cap and its supply can rise or fall. To keep fees down, Ethereum relies increasingly on layer-2 rollups such as Arbitrum, Optimism and Base.