Ethereum: The Decentralized Smart-Contract Blockchain Behind DeFi and NFTs
Ethereum is a decentralized, open-source blockchain whose defining feature is programmable smart contracts: code that runs exactly as written on a global network with no central operator. Conceived by Vitalik Buterin and launched in July 2015, it introduced a general-purpose computing layer on top of a blockchain, where its native cryptocurrency Ether (ETH) pays for computation. In September 2022 the network switched from energy-hungry mining to proof-of-stake, and it now anchors most decentralized finance, NFTs, stablecoins, and a growing stack of layer-2 scaling networks.
Ethereum is a decentralized, open-source blockchain that extends the idea of a shared ledger with a built-in computing layer. Beyond simply tracking who owns a coin, Ethereum lets developers deploy smart contracts: self-executing programs that run exactly as written, with no central operator able to alter or stop them. This makes the network a kind of global, tamper-resistant computer on which decentralized applications (dApps) are built. It was conceived by Vitalik Buterin, who published a white paper in 2013, and the network went live on July 30, 2015. The platform's native cryptocurrency is Ether (ETH), second only to Bitcoin in market value. Ether is the only currency the protocol accepts to pay transaction fees, so it functions less like a stock and more like the fuel that powers computation. Every operation runs inside the Ethereum Virtual Machine (EVM), a deterministic, Turing-complete runtime that produces identical results on every node so the network can reach consensus. The cost of running code is metered in gas: each instruction has a gas price, and users pay a fee combining a base fee (which is burned) and a tip to the validator who includes the transaction. Gas exists to bound computation and prevent infinite loops or spam from clogging the network. Ethereum originally secured itself with proof-of-work mining like Bitcoin, but on September 15, 2022, an upgrade known as The Merge joined the original chain to the proof-of-stake Beacon Chain, replacing miners with validators who stake ETH as collateral. The switch cut the network's energy use by roughly 99.95%. Because base-layer Ethereum is deliberately conservative about throughput, much activity has migrated to layer-2 networks such as rollups, which batch transactions off-chain and post compressed proofs back to Ethereum for security, lowering fees while inheriting the main chain's guarantees. Most of the broader crypto economy is built on these foundations. Decentralized finance (DeFi) protocols offer lending and trading without banks; fiat-pegged stablecoins like USDC settle billions in value daily; and the ERC-721 token standard powers NFTs: The Blockchain Ownership Tokens That Rarely Transfer Copyright. The transparency of this on-chain activity has spawned an analytics industry, queried by tools such as Dune Analytics: SQL-Based Onchain Blockchain Analytics Platform, and underpins applications like a Building a Polymarket CLOB Client in Elixir: Architecture and Cryptography. Ethereum's account-based, fully transparent design contrasts sharply with privacy-focused coins like Monero (XMR): The Privacy-Focused Cryptocurrency Mineable on CPUs, whose entire purpose is to hide the transaction details that Ethereum makes public.