An Ethereum transaction is a cryptographically signed message sent from a wallet address that requests a state change on the Ethereum network. It can transfer ETH, interact with a smart contract (such as swapping tokens or minting an NFT), or deploy a new contract. Once included in a block, the transaction becomes part of Ethereum’s permanent, publicly verifiable ledger.
What an Ethereum transaction does
At a high level, transactions are how users and applications “write” to Ethereum. Sending ETH from one address to another is the simplest example, but many everyday actions are contract calls under the hood. Approving a token allowance, depositing collateral in a lending protocol, or registering a name on an on-chain naming service are all transactions because they change balances, permissions, or contract storage.
Transactions are initiated by externally owned accounts (EOAs), which are controlled by private keys in wallets. Smart contracts can trigger internal calls during execution, but those actions are ultimately paid for and anchored by an originating transaction from an EOA.
Key fields and execution mechanics
Each transaction includes fields that clients and the Ethereum Virtual Machine (EVM) interpret, such as the sender’s signature, recipient address (or contract creation), value (ETH), data (function inputs), a nonce to order transactions from the same account, and gas settings to pay for computation. Under the EIP-1559 fee model, users specify parameters like a max fee and max priority fee; unused gas is not charged, but failed execution still consumes gas because the network performed work.
After broadcast, a transaction sits in the mempool until a validator includes it in a block. Explorers like Etherscan display the transaction hash, status, confirmations, logs, and a receipt that summarizes what happened. Understanding Ethereum transactions matters because they are the core mechanism for security, fees, and finality across wallets, tokens, DeFi, NFTs, and on-chain applications.