Here's a comprehensive summary of the Wikipedia article on Ethereum:

Ethereum is a pioneering open-source, decentralized blockchain platform distinguished by its smart contract functionality. Its native cryptocurrency, Ether (ETH), holds the second-largest market capitalization among all cryptocurrencies, surpassed only by Bitcoin. Conceived in 2013 by programmer Vitalik Buterin—alongside co-founders like Gavin Wood and Joseph Lubin—development began in 2014, culminating in the network's launch on July 30, 2015.

The platform allows users to deploy decentralized applications (DApps), create fungible tokens like ERC-20 and non-fungible tokens (NFTs), and power decentralized finance (DeFi) applications that operate without traditional financial intermediaries. A significant milestone occurred on September 15, 2022, when Ethereum successfully completed "The Merge," transitioning its consensus mechanism from proof-of-work to proof-of-stake, which drastically reduced its energy consumption by over 99%. This makes Ethereum a versatile and evolving digital ecosystem enabling a vast array of blockchain innovations.