Ethereum is a decentralized, open-source blockchain platform designed to support programmable smart contracts and decentralized applications (dApps). Its native asset, ETH, is used to pay transaction fees (called "gas"), secure the network through staking, and serve as the base collateral asset across much of the crypto economy. Launched in July 2015, Ethereum has become the dominant settlement layer for decentralized finance (DeFi), stablecoins, NFTs, tokenization, and Layer 2 scaling infrastructure.