$ETH **Ethereum** is a decentralized blockchain platform enabling smart contracts and dApps. Founded by Vitalik Buterin in 2015, its native token, **ETH**, fuels transactions. Ethereum pioneered DeFi, NFTs, and Web3 innovations. It transitioned from **PoW** to energy-efficient **PoS** in 2022 (The Merge). Scalability upgrades (Rollups, Sharding) aim to reduce fees. Competitors include Solana and BSC, but Ethereum remains the dominant smart contract chain.