Ethereum is a decentralized platform that enables developers to build and deploy smart contracts and decentralized applications (dApps). It operates on a blockchain, which is a distributed ledger technology that ensures transparency and security in transactions. Launched in 2015 by Vitalik Buterin and others, Ethereum has become the second-largest cryptocurrency by market capitalization after Bitcoin. Its native currency, Ether, is used to facilitate transactions and power applications on the network, making it a vital component of the growing decentralized finance (DeFi) ecosystem.