Ethereum (ETH) is a decentralized, open-source blockchain that introduced smart contracts, enabling developers to build decentralized applications (dApps), decentralized finance (DeFi) protocols, NFTs, and more. Launched in 2015 by Vitalik Buterin and a team of co-founders, Ethereum has become the second-largest cryptocurrency by market capitalization after Bitcoin.

ETH, the native cryptocurrency, is used to pay transaction fees (gas), secure the network through staking, and participate in governance of Ethereum-based protocols. Ethereum is transitioning into a proof-of-stake (PoS) blockchain with Ethereum 2.0 upgrades, significantly reducing energy consumption while maintaining high security and decentralization. Its flexible, programmable blockchain architecture has made Ethereum the foundation for much of the DeFi and NFT ecosystems.