Ethereum
The second-largest cryptocurrency platform, known for smart contracts and decentralized applications (dApps).
What is Ethereum?
Ethereum is a decentralized, open-source blockchain platform launched in 2015 by Vitalik Buterin. Its native cryptocurrency is Ether (ETH). Ethereum's defining feature is its Turing-complete smart contract functionality — self-executing code stored on the blockchain that automatically enforces the terms of an agreement without intermediaries. Smart contracts enable decentralized applications (dApps), decentralized finance (DeFi) protocols, NFTs, and token issuance (ERC-20 tokens). In 2022, Ethereum transitioned from energy-intensive Proof of Work to Proof of Stake (the 'Merge'), reducing its energy consumption by ~99.95%. Unlike Bitcoin's fixed supply, Ethereum has no hard supply cap, though fee-burning mechanisms introduced in 2021 have made it effectively deflationary at times.
Example
Ethereum's smart contracts enabled the $70 billion DeFi ecosystem as of 2024: users can lend, borrow, and trade crypto assets through protocols like Uniswap and Aave without any bank or broker. The same infrastructure powers the NFT market — when an NFT is sold on OpenSea, a smart contract on Ethereum automatically transfers ownership and distributes royalties, all without a centralized platform holding funds.