Ethereum is a decentralized, open-source blockchain platform that enables developers to build and deploy smart contracts and decentralized applications (dApps). Launched in 2015 by Vitalik Buterin and others, Ethereum goes beyond simple transactions, allowing programmable, self-executing agreements without the need for intermediaries. Its native cryptocurrency, Ether (ETH), powers the network by facilitating transactions and incentivizing validators. With the transition to a proof-of-stake consensus mechanism through Ethereum 2.0, the platform has significantly improved its energy efficiency and scalability. Ethereum continues to be a foundational layer for innovation in decentralized finance (DeFi), non-fungible tokens (NFTs), and the broader Web3 ecosystem.