$ETH Ethereum is a decentralized blockchain platform that allows developers to build and deploy smart contracts and decentralized applications (DApps). It uses a cryptocurrency called Ether (ETH) as its native token. Ethereum introduced the concept of smart contracts, which are self-executing agreements written in code. It has a vast ecosystem and is the backbone for most DeFi (Decentralized Finance) projects, NFTs, and DAOs. Ethereum transitioned from a Proof of Work (PoW) to a Proof of Stake (PoS) mechanism in 2022, making it more energy-efficient.