What is Ethereum and how does it work? (ETH explained)

Core Architecture of Ethereum

1. Ethereum operates as a decentralized, open-source blockchain platform that enables the execution of smart contracts without intermediaries.

2. Its native cryptocurrency, Ether (ETH), serves both as a digital currency and as fuel for computational operations across the network.

3. Every node in the Ethereum network maintains a full copy of the ledger, ensuring transparency and resistance to censorship or single-point failure.

4. The Ethereum Virtual Machine (EVM) executes bytecode instructions embedded in smart contracts, guaranteeing deterministic outcomes regardless of the executing node’s hardware or software environment.

5. Block production follows a consensus mechanism—currently Proof-of-Stake (PoS) after the Merge upgrade—which replaces energy-intensive mining with staking-based validation.

Smart Contracts and Decentralized Applications

1. Smart contracts are self-executing agreements written in Solidity or Vyper, compiled into EVM-compatible bytecode, and deployed at unique addresses on-chain.

2. Once deployed, their logic cannot be altered unless explicitly designed with upgradeability patterns such as proxy contracts or governance-controlled modules.

3. dApps leverage these contracts to deliver services ranging from decentralized exchanges to lending protocols, NFT marketplaces, and identity verification systems.

4. Interaction with dApps occurs through wallet interfaces like MetaMask, which sign transactions containing function calls, parameters, and gas limits before broadcasting them to the network.

5. Each operation consumes gas—a unit measuring computational effort—priced in ETH, preventing spam and allocating resources fairly among users.

Ethereum’s Token Standards

1. ERC-20 defines fungible tokens used for utility, governance, or representation of assets, with standardized functions like transfer(), balanceOf(), and totalSupply().

2. ERC-721 introduced non-fungible tokens (NFTs), enabling unique digital ownership verified via distinct token IDs and metadata URIs stored on-chain or off-chain.

3. ERC-1155 allows semi-fungible tokens, supporting multiple token types—including both fungible and non-fungible—in a single contract deployment, reducing gas overhead.

4. These standards ensure interoperability across wallets, explorers, and marketplaces, allowing seamless integration without custom parsing logic.

5. Developers rely on audited reference implementations and widely adopted libraries such as OpenZeppelin to minimize vulnerabilities during contract development.

Transaction Lifecycle and Network Fees

1. A user initiates a transaction by signing it with their private key, specifying recipient address, value, data payload, nonce, and gas parameters.

2. The signed transaction is broadcast to the mempool, where validators select high-priority transactions based on gas price and inclusion incentives.

3. Upon inclusion in a block, the EVM processes all state changes atomically: if any step fails, the entire transaction reverts, preserving ledger consistency.

4. Base fee per gas is dynamically adjusted each block according to network congestion, while priority fee goes directly to validators as a tip.

5. Finality is achieved after two additional blocks under PoS, meaning confirmed transactions become irreversible within seconds rather than minutes.

Frequently Asked Questions

Q: Can ETH be mined after the Merge? No. Ethereum no longer uses Proof-of-Work. Mining has been replaced entirely by staking, where participants lock up 32 ETH to run validator nodes and earn rewards.

Q: Is ETH a security under U.S. regulatory frameworks? The SEC has not classified ETH as a security. Multiple legal analyses and statements from regulators indicate ETH functions primarily as a commodity and medium of exchange within its ecosystem.

Q: What happens if a smart contract contains a bug? Bugs may lead to unintended behavior or loss of funds. Since code is immutable post-deployment, mitigation relies on external interventions like protocol freezes, emergency upgrades, or community-driven rescue mechanisms—if pre-designed.

Q: How does Ethereum differ from Bitcoin in terms of scripting capability? Bitcoin uses a deliberately limited stack-based language (Script) focused on basic transaction validation. Ethereum employs a Turing-complete virtual machine, enabling arbitrary logic, persistent storage, and complex interaction between contracts.