Ethereum is an open-source blockchain platform launched in 2015 by Vitalik Buterin and a team of developers. Its key innovation was the introduction of smart contracts, enabling the creation of decentralized applications (DApps) on the blockchain. This made Ethereum the foundation for decentralized finance (DeFi), non-fungible tokens (NFTs), and many innovative applications. Supported by the Ethereum Foundation and a global developer community, Ethereum is the second-largest cryptocurrency after Bitcoin and plays a central role in expanding the blockchain ecosystem.