What is Ethereum?

Ethereum is a decentralized, open-source blockchain that introduced the world to programmable money through smart contracts. While Bitcoin proved that decentralized digital currency was possible, Ethereum expanded the vision to decentralized applications — programs that run exactly as coded without downtime, censorship, or third-party interference. Launched in 2015, Ethereum has become the foundation for decentralized finance (DeFi), NFTs, DAOs, and an entire ecosystem of innovation built on trustless computation.

The History of Ethereum

Ethereum was proposed in late 2013 by Vitalik Buterin, a 19-year-old programmer and Bitcoin Magazine co-founder who recognized that Bitcoin's scripting language was too limited for general-purpose applications. Rather than building features one by one onto Bitcoin, Buterin envisioned a blockchain with a built-in Turing-complete programming language that could power any conceivable application.

The project gathered a founding team including Gavin Wood (who wrote the Yellow Paper formally specifying the EVM), Joseph Lubin (who later founded ConsenSys), Charles Hoskinson (who later created Cardano), and several other co-founders. Ethereum held its crowdfunding sale in mid-2014, raising approximately 31,500 BTC (worth roughly $18 million at the time). The genesis block was mined on July 30, 2015.

Major Milestones

How Ethereum Works

Nodes and the Network

Ethereum runs on a global network of thousands of computers (nodes) that each maintain a copy of the entire blockchain. Anyone can run a node, which makes the network censorship-resistant — no single entity controls it. There are three types of nodes: full nodes (store complete blockchain state), archive nodes (store all historical states), and light nodes (store only block headers and request data on demand).

Transactions and the EVM

Every action on Ethereum is a transaction: sending ETH, calling a smart contract function, or deploying a new contract. Transactions are broadcast to the network, included in blocks by validators, and executed by the Ethereum Virtual Machine (EVM). The EVM is a sandboxed runtime environment that processes bytecode deterministically — every node running the same transaction gets the same result, guaranteeing consensus.

Consensus: Proof of Stake

Since The Merge in September 2022, Ethereum uses Proof of Stake (PoS) for consensus. Validators stake 32 ETH as collateral and are randomly selected to propose new blocks. Other validators attest (vote) on the validity of proposed blocks. Validators who act honestly earn rewards; validators who act maliciously or go offline get slashed (lose a portion of their stake). This replaced the energy-intensive Proof of Work mining that Ethereum used for its first seven years.

Blocks and Slots

Ethereum produces a new block every 12 seconds (one slot). Slots are grouped into epochs of 32 slots (6.4 minutes). Each block contains a list of transactions, a reference to its parent block (forming the chain), and the state root (a cryptographic summary of all account balances and contract storage). The block proposer earns priority fees (tips) from transactions plus a protocol reward for participating in consensus.

ETH: The Native Asset

ETH (Ether) is the native cryptocurrency of Ethereum. It serves multiple roles in the ecosystem:

• Gas payments: Every transaction and smart contract execution requires gas fees paid in ETH. This is the primary utility that creates constant demand for ETH.
• Staking: Validators lock up 32 ETH to participate in consensus. This secures the network and earns validators approximately 3-4% annual rewards.
• Store of value: With EIP-1559 burning a portion of every transaction's base fee, ETH can become deflationary during high network activity — more ETH is burned than issued, reducing total supply.
• DeFi collateral: ETH is the most widely used collateral in DeFi lending protocols, enabling users to borrow stablecoins against their ETH holdings.

The Ethereum Ecosystem

Decentralized Finance (DeFi)

DeFi protocols on Ethereum enable lending (Aave, Compound), trading (Uniswap, Curve), derivatives (GMX, dYdX), and asset management without intermediaries. Hundreds of billions of dollars in value are locked in DeFi smart contracts. DeFi was the first "killer app" that demonstrated Ethereum's value beyond simple token transfers.

NFTs and Digital Art

Ethereum hosts the vast majority of high-value NFTs through the ERC-721 and ERC-1155 standards. From generative art (Art Blocks) to profile pictures (CryptoPunks, BAYC) to music and photography, NFTs represent a new paradigm for digital ownership and creator monetization.

DAOs (Decentralized Autonomous Organizations)

DAOs use smart contracts and governance tokens to enable collective decision-making without traditional corporate structures. Members vote on proposals using their tokens. Examples include MakerDAO (which governs the DAI stablecoin), Nouns DAO (which allocates treasury funds to community projects), and Gitcoin DAO (which funds public goods in the Ethereum ecosystem).

Layer 2 Networks

Layer 2 (L2) networks like Arbitrum, Optimism, Base, and zkSync process transactions off-chain and post compressed proofs back to Ethereum. They inherit Ethereum's security while providing 10-100x lower fees and higher throughput. L2s are a core part of Ethereum's scaling strategy and are where most new user activity is concentrated.

The Merge: Ethereum's Biggest Upgrade

On September 15, 2022, Ethereum completed The Merge — a transition from Proof of Work (PoW) to Proof of Stake (PoS) that had been planned since Ethereum's inception. This was one of the most significant technical achievements in blockchain history: migrating a live network securing hundreds of billions of dollars without any downtime.

• Energy reduction: Ethereum's energy consumption dropped by approximately 99.95%, from the equivalent of a medium-sized country to a small town.
• Issuance reduction: ETH issuance dropped by roughly 90%, from ~13,000 ETH/day (mining rewards) to ~1,700 ETH/day (staking rewards). Combined with EIP-1559 burning, ETH became net deflationary during periods of high activity.
• Validator accessibility: Anyone with 32 ETH can become a validator (or use liquid staking protocols like Lido for smaller amounts). This is more accessible than buying specialized mining hardware.

Ethereum Roadmap: The Future

Ethereum's development continues with several major phases designed to scale the network to millions of users:

• The Surge: Massively scale transaction throughput through rollups and data sharding. EIP-4844 (proto-danksharding), shipped in March 2024 with Dencun, introduced blob transactions that reduced L2 fees by up to 100x. Full danksharding will further expand data availability for rollups.
• The Verge: Introduce Verkle trees to replace Merkle Patricia tries, enabling stateless clients that can verify blocks without storing the entire state. This makes running a node much lighter and more accessible.
• The Purge: Reduce the storage burden on nodes by expiring old historical data. Nodes would no longer need to store the entire history of the blockchain, only recent and relevant state.
• The Splurge: A collection of miscellaneous improvements including account abstraction (ERC-4337), proposer-builder separation, and other protocol refinements that improve user experience and network efficiency.

Ethereum vs Bitcoin at a Glance

For a comprehensive comparison, read our dedicated Ethereum vs Bitcoin guide. Here is a quick summary:

Frequently Asked Questions