$ETH Ethereum ($ETH) is a decentralized, open-source blockchain system that features smart contract functionality. Launched in 2015 by Vitalik Buterin and others, it enables developers to build decentralized applications (dApps) without relying on traditional intermediaries. Ether (ETH) is its native cryptocurrency, used to pay for transaction fees and computational services on the network. Ethereum introduced innovations like decentralized finance (DeFi) and non-fungible tokens (NFTs), significantly expanding blockchain's use cases beyond simple transactions. In 2022, Ethereum transitioned from proof-of-work to proof-of-stake consensus through "The Merge," reducing its energy consumption by over 99%. It remains a foundational pillar in the Web3 ecosystem.