Ethereum

Ethereum is a blockchain platform, launched in 2015 and proposed by Vitalik Buterin, that goes beyond simple payments by running programmable code called smart contracts. While Bitcoin's ledger mainly tracks who owns which coins, Ethereum functions as a shared world computer: developers deploy applications directly onto the blockchain, and those applications run exactly as written without any company operating a server.

The network's native currency is ether (ETH), which users pay as gas fees to execute transactions and contracts. Most of the crypto ecosystem beyond Bitcoin was built on or inspired by Ethereum: decentralized exchanges, lending protocols, stablecoins like USDC and DAI, and NFTs all began as Ethereum smart contracts. For example, a user can swap one token for another on a decentralized exchange like Uniswap, where the trade is executed entirely by a contract on Ethereum rather than by a brokerage.

A common misconception is that Ethereum still relies on energy-intensive mining; the network switched from proof of work to proof of stake in September 2022 (an event called the Merge), cutting its energy use by over 99 percent. Ether has no fixed supply cap like Bitcoin's 21 million, but part of every transaction fee is burned, which offsets new issuance.