Ethereum glossary
Gas fees, smart contracts and validators. Decode the Ethereum terms that turn up in wallet prompts, dev chats and staking discussions.
ABI
The Application Binary Interface: the rules and interface description used to encode and decode contract interactions.
Account abstraction
An approach that makes blockchain account authorization and operation more programmable.
Allowance
The amount an ERC-20 token owner has authorized a particular spender to transfer.
Atomic transaction
An operation whose included state changes succeed together or are rolled back together under the execution rules.
Attestation
A validator’s signed vote about the blockchain history it considers valid.
Base fee
Ethereum’s protocol-set execution fee per gas unit, which adjusts with block demand and is burned.
Bundler
An ERC-4337 participant that packages UserOperations into transactions sent through an EntryPoint contract.
Bytecode
Machine-oriented instructions that a virtual machine executes, often produced by compiling source code.
Calldata
The input data supplied to an Ethereum transaction or contract call.
Checkpoint
A designated block used as a reference point in a consensus process.
Contract account
An Ethereum account associated with deployed code that runs when it is called.
Contract deployment
The onchain creation of a contract account with executable code.
Contract upgrade
A change to a contract system’s behavior through a mechanism designed to allow it.
Contract verification
The process of matching published source code and compiler settings to a deployed contract’s bytecode.
Delegatecall
An EVM call that runs another contract’s code using the calling contract’s storage and context.
EIP
An Ethereum Improvement Proposal: a document describing a proposed technical change or standard.
EIP-1559
The Ethereum upgrade that introduced a dynamic execution base fee and revised transaction fee settings.
Epoch
A group of slots used to organize consensus timing and related duties.
ERC-1155
An Ethereum standard that lets one contract manage multiple token types and transfer them in batches.
ERC-20
An Ethereum interface standard for fungible tokens, including balances, transfers and spending allowances.
ERC-4626
An Ethereum standard for tokenized vaults that manage an ERC-20 asset and issue vault shares.
ERC-721
An Ethereum token standard for individually identified non-fungible tokens.
Ether
Ethereum’s native cryptocurrency, usually written as ETH, used for transaction fees and staking.
Ethereum
A blockchain that runs programmable accounts and applications, with ether as its native asset.
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