Ethereum (ETH) is the second largest cryptocurrency after Bitcoin, known for its ability to run smart contracts and decentralized applications (DApps). It was launched in 2015 by Vitalik Buterin, aiming to provide a flexible blockchain environment that supports innovation in decentralized finance (DeFi) and non-fungible tokens (NFTs). Ethereum currently relies on a Proof of Stake (PoS) mechanism after the 'Merge' upgrade, making it more energy efficient. It boasts a strong network of developers and continues to develop its technologies such as layer two improvements to reduce gas fees. Ethereum is considered the cornerstone of the blockchain ecosystem and has significant growth potential in the future.