Ethereum is a decentralized, open-source blockchain that enables smart contracts and decentralized applications (DApps). Created by Vitalik Buterin and launched in 2015, Ethereum allows developers to build complex programs that run exactly as programmed, without the risk of downtime or censorship. Ether (ETH) is its native currency, used for paying gas fees and powering transactions. With the shift to Proof of Stake (Ethereum 2.0), Ethereum has become more energy-efficient and scalable, supporting a massive ecosystem of DeFi, NFTs, and gaming.