Ethereum is a decentralized blockchain platform that enables developers to build and deploy decentralized applications (dApps) and smart contracts. Launched in 2015 by Vitalik Buterin and others, Ethereum extends blockchain technology beyond digital currency to allow programmable contracts executed automatically when preset conditions are met.

At its core, Ethereum operates using its native cryptocurrency called Ether (ETH), which fuels the network by paying transaction fees and computational costs for running applications. Unlike Bitcoin's focus on peer-to-peer digital currency, Ethereum provides a flexible platform for creating a variety of decentralized solutions in finance, gaming, real estate, and more.

Ethereum uses a consensus mechanism called Proof-of-Stake (PoS), which is more energy-efficient than Bitcoin's Proof-of-Work, helping to secure the network while validating transactions. The Ethereum Virtual Machine (EVM) executes smart contracts, enabling trustless and automated agreements without the need for intermediaries.

Through these features, Ethereum aims to decentralize the world by enabling transparent, secure, and programmable interactions online, revolutionizing how applications are built and operated globally.