Ethereum

Overview

Ethereum extended Bitcoin’s blockchain model with a general-purpose, Turing-complete virtual machine, letting developers deploy arbitrary “smart contracts” rather than just transferring a native coin. It is the foundation for most of the DeFi, NFT, and decentralized application ecosystem, and the most widely used smart-contract platform by total value secured.

History

Origins

Vitalik Buterin proposed Ethereum in a late-2013 whitepaper after his involvement with Bitcoin Magazine convinced him that Bitcoin’s scripting language was too limited for building general applications. Gavin Wood formalized the protocol in the 2014 “Yellow Paper” and wrote the initial C++ and Solidity tooling. The project’s founding team also included Charles Hoskinson (who later left to found Cardano), Anthony Di Iorio, Joseph Lubin (who went on to found ConsenSys), Mihai Alisie, Amir Chetrit, and Jeffrey Wilcke.

The network launched its first live version, “Frontier,” on July 30, 2015.

Funding

Ethereum was funded by a public presale of ether in July–August 2014, run directly by the Ethereum Foundation. It raised approximately 31,591 BTC, worth around $18.3 million at the time — a modest sum by later ICO standards, but one that set the template for token-based project funding that thousands of subsequent chains would copy.

Technology

Consensus Algorithm

Ethereum ran on Proof of Work from launch until “The Merge” on September 15, 2022, when it switched to Proof of Stake. Its current consensus design, sometimes called Gasper, combines LMD-GHOST fork-choice with Casper FFG finality, and validators stake ETH (32 ETH to run a validator directly, or any amount via pooled/liquid staking) to propose and attest to blocks.

Network & Ecosystem

Ethereum anchors the broader “EVM-compatible” ecosystem: chains and layer-2 networks including BNB Chain, Polygon, Avalanche’s C-Chain, Arbitrum, Optimism, and Base all run the same virtual machine and tooling, letting contracts and developer tooling move between them with minimal changes. Ethereum itself has scaled primarily through rollups — layer-2 networks that execute transactions off-chain and post compressed proofs or data back to Ethereum — rather than by increasing base-layer throughput directly.

Smart Contracts

Ethereum introduced the EVM, a sandboxed, Turing-complete runtime in which contracts are typically written in Solidity (or, less commonly, Vyper) and compiled to EVM bytecode. Token standards defined on Ethereum — ERC-20 for fungible tokens and ERC-721 for NFTs — became the de facto standards adopted across the rest of the industry.

Use Cases

Ethereum’s original goal was to be a “world computer”: a general-purpose platform for decentralized applications rather than a single-purpose currency. In practice, it has become the primary settlement and liquidity layer for decentralized finance (lending, exchanges, stablecoins), NFTs, and much of the tokenized-asset experimentation in crypto, while increasingly delegating everyday transaction execution to its layer-2 rollup ecosystem.

Controversies & Incidents

• The DAO hack and hard fork (2016): An attacker exploited a reentrancy bug in “The DAO,” a decentralized venture fund built on Ethereum, draining roughly 3.6 million ETH (around $50–60 million at the time). The Ethereum community controversially voted to hard-fork the chain to reverse the theft and return funds, which most of the ecosystem followed as “Ethereum” — but a minority rejected the fork on immutability grounds and continued the original chain as Ethereum Classic (ETC).
• Scalability and gas fees: During peak demand (notably the 2017 ICO boom and 2020–2021 DeFi/NFT booms), network congestion drove transaction fees to tens or even hundreds of dollars, fueling both the rise of competing “Ethereum killer” chains and Ethereum’s own multi-year rollup-centric scaling roadmap.
• Pre-Merge energy criticism: Like Bitcoin, Ethereum’s proof-of-work era drew significant criticism over electricity consumption; The Merge is estimated to have cut the network’s energy usage by more than 99%.
• Regulatory scrutiny: Ethereum has faced periodic questions from regulators — including the U.S. SEC — about whether ETH should be classified as a security, given its 2014 token sale, though U.S. regulators have generally treated ETH as a commodity rather than a security in recent years.