Ethereum
The world computer. The DeFi backbone. The NFT birthplace. The most controversial gas bill in tech history.
What is Ethereum?
Ethereum (ETH) is a programmable blockchain platform that allows developers to build and deploy smart contracts and decentralized applications (dApps). Unlike Bitcoin which primarily serves as digital money, Ethereum is a global computing platform — the infrastructure that most of DeFi, NFTs, and Web3 is built on.
Launched in 2015 by Vitalik Buterin and others, Ethereum introduced the concept of a Turing-complete blockchain — one that can execute any programmable logic. This made it the foundation for the entire DeFi and NFT explosion of 2020–2022, and it remains the dominant smart contract platform by total value locked.
📜 Smart Contracts: Vending Machines That Don't Trust You
A smart contract is code that lives on the blockchain and executes automatically when its conditions are met. It doesn't need a lawyer, a judge, or a middleman. It runs exactly as written — every time, for everyone, with no exceptions.
Vending machine analogy: put in the right amount, press the right button, get your item. The machine doesn't negotiate. It doesn't trust you. It executes the contract you both agreed to. Smart contracts are the same concept, except they can be arbitrarily complex — handling financial agreements, governance votes, NFT mints, token swaps, insurance claims, and more.
The catch: smart contracts are immutable once deployed. A bug in the code is a permanent bug. Poorly written smart contracts have cost billions in exploits. "The code is law" is both the power and the peril.
🎟️ ERC-20, ERC-721 & ERC-1155: The Token Standards That Built Web3
ERC-20
The standard for fungible tokens — interchangeable tokens where one is identical to any other. Every DeFi token, stablecoin (USDC, DAI), and governance token (UNI, AAVE) uses ERC-20. This standard is what made the ICO boom of 2017 possible and still underlies virtually all DeFi.
Examples: USDC, DAI, UNI, LINK, MATIC
ERC-721
The NFT standard. Each ERC-721 token is unique and non-fungible — no two are identical. Your Bored Ape, CryptoPunk, or Hunger4Crypto Soulbound Badge is an ERC-721 token. Ownership is recorded on-chain and publicly verifiable.
Examples: CryptoPunks, BAYC, ENS names
ERC-1155
A hybrid standard supporting both fungible and non-fungible tokens in the same contract. More gas-efficient for batch transfers. Popular in gaming and platforms that need both item types — e.g., 1,000 identical health potions AND 1 unique legendary sword.
Examples: OpenSea, gaming platforms
⛽ Gas Fees: Surge Pricing for Math
Every operation on Ethereum costs gas — units of computational work. Gas fees are what you pay validators to process your transaction. During high-demand periods (major NFT drops, DeFi launches), fees can skyrocket as everyone competes to get their transaction included in the next block.
EIP-1559 (implemented in 2021) improved the fee market: it introduced a base fee (burned, not paid to validators) plus a priority tip. This made fees more predictable and simultaneously reduced ETH supply — making ETH deflationary during high-activity periods.
Tips for minimizing gas: transact during off-peak hours (weekday mornings UTC), use Layer 2 networks for regular activity, and always check Etherscan's gas tracker before submitting expensive transactions.
💎 Ethereum Staking: Earning While the Network Runs
Since "The Merge" in September 2022, Ethereum switched from Proof-of-Work to Proof-of-Stake. Validators stake 32 ETH as collateral and are randomly selected to propose and attest to new blocks. In exchange, they earn staking rewards (~3–5% APY depending on total staked ETH).
Don't have 32 ETH? Liquid staking protocols like Lido (stETH) and Rocket Pool (rETH) let you stake any amount and receive a liquid token representing your staked position — which you can then use in DeFi while still earning staking rewards.
The environmental impact of The Merge was immediate and dramatic: Ethereum's energy consumption dropped by over 99.95%. From an environmental standpoint, Proof-of-Stake Ethereum is roughly as energy-intensive as a small office building.
What is Ether (ETH)?
ETH is the native cryptocurrency of the Ethereum network. It's used to pay gas fees for every transaction and smart contract interaction. It's also staked by validators to secure the network, and used as collateral across countless DeFi protocols.
What is 'The Merge'?
The Merge (September 2022) was Ethereum's transition from Proof-of-Work to Proof-of-Stake consensus. It reduced Ethereum's energy consumption by over 99.95% and replaced miners with validators who stake ETH instead of running mining hardware.
What is a dApp?
A decentralized application (dApp) is an application that runs on a blockchain rather than centralized servers. The backend is smart contracts. There's no company that can shut it down or change the rules. Uniswap, Aave, OpenSea, and Hunger4Crypto's reputation system are all dApps.
What is an Ethereum wallet address?
An Ethereum wallet address is a 42-character string starting with '0x' — your public identifier on the Ethereum blockchain. Share it freely to receive ETH and tokens. Never share your private key or seed phrase.
What is Solidity?
Solidity is the primary programming language for writing Ethereum smart contracts. It's a statically typed language with syntax similar to JavaScript. Smart contracts written in Solidity are compiled and deployed to the Ethereum Virtual Machine (EVM) where they run immutably.
What is the Ethereum Virtual Machine (EVM)?
The EVM is the runtime environment for smart contracts on Ethereum. It executes contract code identically across all nodes, ensuring the same input always produces the same output — which is what makes trustless computation possible. Many other chains (Polygon, Avalanche, BSC) are EVM-compatible.
Frequently Asked Questions
What is Ethereum?+
Ethereum is a programmable blockchain platform that allows developers to build and deploy smart contracts and decentralized applications (dApps). Launched in 2015, it's the dominant platform for DeFi, NFTs, and Web3 applications. Unlike Bitcoin, which primarily functions as digital money, Ethereum is a global computing platform.
What is the difference between Bitcoin and Ethereum?+
Bitcoin is designed primarily as a decentralized digital currency and store of value. Ethereum is a programmable blockchain built for smart contracts and decentralized applications. Bitcoin prioritizes security and monetary simplicity; Ethereum prioritizes programmability and versatility. Both are major Layer 1 blockchains serving different purposes.
How do gas fees work on Ethereum?+
Gas fees are payments to validators for processing your transactions and smart contract operations. They're denominated in 'gwei' (a unit of ETH) and fluctuate based on network demand. The fee = gas units used × gas price. Higher fees get priority inclusion in the next block. EIP-1559 introduced a burned base fee plus an optional priority tip to validators.
What is Ethereum staking?+
Ethereum staking involves locking up 32 ETH (or any amount via liquid staking protocols) to become a network validator. Validators propose and attest to new blocks and earn staking rewards (~3–5% APY). Since The Merge in 2022, staking replaced energy-intensive mining as Ethereum's security mechanism.
What are ERC-20 tokens?+
ERC-20 is the standard for fungible tokens on Ethereum — interchangeable tokens where each unit is identical to any other. USDC, DAI, UNI, LINK, and thousands of other tokens follow this standard. ERC-20 is what made the ICO boom of 2017 and the entire DeFi ecosystem possible.
What are Layer 2 solutions for Ethereum?+
Layer 2 solutions process transactions off of Ethereum's main chain (Layer 1) for speed and cost, then periodically settle the results back to Ethereum for security. Major Ethereum L2s include Arbitrum, Optimism, Base, and zkSync. They offer transactions for cents versus dollars on mainnet, while inheriting Ethereum's security.
Our editorial team combines years of blockchain industry experience with a commitment to clear, unbiased crypto education. All content is reviewed for accuracy and updated regularly.