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Arbitrum DAO glossary


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Arbitrum's governance token, an ERC-20 token native to the Arbitrum One chain. Owning $ARB makes you a member of the Arbitrum DAO and allows you to participate in Arbitrum's on-chain governance.

$ARB reverse gateway

A series of smart contracts responsible for bridging $ARB between Arbitrum One and Ethereum. The $ARB token is native to Arbitrum One, meaning it's minted within a smart contract that lives on the Arbitrum One chain. The "reverse" gateway keeps the full $ARB supply escrowed in Arbitrum One, and mints or burns the Layer 1 (L1) token representation upon deposits/withdrawals. The reverse gateway is often compared to the Standard Token gateway", which mints/burns on Layer 2 (L2).

Active Validator

A staked Validator that makes disputable assertions to advance the state of an Arbitrum chain or to challenge the validity of others' assertions. (Not to be confused with the Sequencer ).


A mechanism that distributes tokens to qualifying wallet addresses, usually based on on-chain activity. The Arbitrum Foundation airdrop distributed $ARB tokens to eligible wallet addresses according to the airdrop eligibility and distribution criteria specified in our overview of airdrop eligibility and specifications.

Arbitrum AnyTrust Chain

An Arbitrum chain that implements the Arbitrum AnyTrust Protocol.

Arbitrum AnyTrust Protocol

An Arbitrum protocol that manages data availability with a permissioned set of parties known as the Data Availability Committee (DAC). This protocol reduces transaction fees by introducing an additional trust assumption for data availability in lieu of Ethereum's Trustless data availability mechanism. Arbitrum Nova is an example of an AnyTrust chain; Arbitrum One is an alternative chain that implements the purely trustless (and more L1-gas intensive) Arbitrum Rollup Protocol.

Arbitrum chain

A blockchain that runs on the Arbitrum protocol. Arbitrum chains are EVM compatible, and use an underlying EVM chain (e.g., Ethereum) for settlement and for succinct fraud-proofs (as needed). Arbitrum chains come in two forms: Arbitrum Rollup Chains and Arbitrum AnyTrust Chains.

Arbitrum Chain owner

An entity with the affordance to upgrade Arbitrum core protocol contracts and set various system parameters. Arbitrum One has two chain owners: the Arbitrum DAO and the Security Council.

Arbitrum DAO

The worldwide community of $ARB token holders and Delegates. Governs the Arbitrum One chain, the Arbitrum Nova chain, The Constitution of the Arbitrum DAO, and the Security Council.

Arbitrum DAO governance forum

Public forum for viewing and discussing Arbitrum Improvement Proposal (AIP)s and other governance-related topics.

Arbitrum DAO Treasury

A smart contract on the Arbitrum One chain that contains tokens collectively controlled by the Arbitrum DAO.

Arbitrum Improvement Proposal (AIP)

A Governance proposal as defined by The Constitution of the Arbitrum DAO. There are two types of AIPs: Constitutional AIPs and Non-constitutional AIPs.

Arbitrum Nitro

Current Arbitrum tech stack; runs a fork of Geth and uses WebAssembly as its underlying VM for fraud proofs.

Arbitrum Nova

The first Arbitrum AnyTrust Chain running on Ethereum mainnet. Introduces cheaper transactions; great for gaming and social use-cases. Implements the Arbitrum AnyTrust Protocol, not the Arbitrum Rollup Protocol protocol.

Arbitrum One

The first Arbitrum Rollup Chain running on Ethereum mainnet. Fully trustless; inherits Ethereum's base-layer security guarantees without introducing additional trust assumptions; great for decentralized finance and other use-cases that demand L1-level trustlessness.

Arbitrum Rollup Chain

An Arbitrum chain that implements the Arbitrum Rollup Protocol.

Arbitrum Rollup Protocol

A trustless, permissionless Arbitrum protocol that uses its underlying base layer for data availability and inherits its security. This protocol is implemented by our Arbitrum One chain.

Child chain

An Arbitrum Chain that settles to an underlying Parent chain . For example, Arbitrum One and Arbitrum Nova are child chains of Ethereum.

Claimable airdrop period

The time period in which eligible $ARB token recipients were able to claim their tokens.

Claimed airdrop tokens

$ARB tokens claimed from the Token Distributor Contract during the Claimable airdrop period.

Constitutional AIP

As opposed to Non-constitutional AIP. The stricter of the two types of proposals. Constitution proposals requires a longer delay before effectuation. Refer to The Constitution of the Arbitrum DAO for a more precise definition.

Core Governor

Governance contract responsible for creating Constitutional AIPs, aka "core proposals."

DAO-governed chains

A permissioned set of parties responsible for enforcing data availability in an Arbitrum AnyTrust Protocol chain. See Introducing AnyTrust Chains: Cheaper, Faster L2 Chains with Minimal Trust Assumptions to learn more.

Data Availability Committee (DAC)

A permissioned set of parties responsible for enforcing data availability in an Arbitrum AnyTrust Protocol chain. See Introducing AnyTrust Chains: Cheaper, Faster L2 Chains with Minimal Trust Assumptions to learn more.

Decentralized apps (dApps)

Apps that combine blockchain-based smart contracts with frontend user interfaces. Arbitrum makes it easy for you to build fast Ethereum dApps that inherit Ethereum's security guarantees while keeping costs low for end-users.


A party that has the ability to vote on Arbitrum Governance proposals. Could be an $ARB token holder or someone to whom other $ARB token holders have delegated their voting power.

Emergency action

A specific type of governance action used by the Security Council in emergency situations, such as fixing a critical vulnerability. As opposed to Non-emergency action.

Ethereum consensus layer (CL)

Facilitates staking, peer-to-peer consensus, block creation, and attestations for Ethereum's Layer 1 (L1) network. Powered by consensus-layer clients like Prysm, Teku, and Lighthouse.

Ethereum execution layer (EL)

Facilitates Smart contract logic and execution for Ethereum's Layer 1 (L1) network. Powered by execution-layer clients like Geth, Nethermind, and Besu.

Exclude Address

Special address (0x00000000000000000000000000000000000a4b86) that ARB holders can delegates can their votes to so-as not to be included in proposals' quorum calculation. Notable, the Arbitrum DAO treasury has its votes excluded.

Foundation Vesting Wallet

Smart contract wallet that stores the The Arbitrum Foundation's tokens; tokens vest linearly over the course of 4 years, as specified [AIP 1.1](


An execution-layer client that defines the Ethereum state transition function and handles network-layer logic like transaction memory pooling. Arbitrum Nitro utilizes a fork of Geth to implement Arbitrum's state transition function.


The way that decisions get made. Governance of web2 technologies traditionally depends on a board of directors abiding by trusted social contracts, while governance of web3 technologies depends on Decentralized Autonomous Organizations (DAOs) using Trustless Smart contracts.

Governance Action Contract

Contract with the logic to be used for the execution of a Governance proposal; see governance contracts docs for details.

Governance proposal

A proposal to change some aspect of Arbitrum DAO's governance protocol. There are two types of Arbitrum DAO governance proposals: Constitutional AIPs and Non-constitutional AIPs.

Governance token

A particular type of token that allows token-holders to vote on governance proposals. $ARB is an example of a governance token; it allows token-holders to create and vote on Arbitrum DAO Governance proposals.


In the context of Ethereum, immutability refers to the inability to change the data recorded in the blockchain. You can think of Ethereum's blockchain as a decentralized, distributed linked-list data structure that stores the entire history of transactions within a globally distributed network of computers running Ethereum client software.

The client software implements a protocol that stores transaction history within a data structure known as a "block"; blocks are linked to other blocks in chronological order. Because each block contains a cryptographic hash of the previous block, it's extremely difficult to change transaction data after it's been recorded as canonical by the network.

L1 Base Fee

Transaction fee component paid by a user to a chain's Sequencer to refund the Sequencer for its batch-posting fees.

L1 Surplus Fee

Transaction fee component charged as proportion of L1 base fee, beyond, e.g., the amount strictly necessary for the Sequencer to break even; collected by the Arbitrum DAO.

L2 Base Fee

Transaction fee component that covers the minimum cost of Arbitrum transaction execution; collection by the Arbitrum DAO on Arbitrum One and by the DAO + the Data Availability Committee (DAC) on Arbitrum Nova.

L2 Surplus Fee

Transaction fee component that covers the cost beyond that covered by the L2 Base Fee during chain congestion; collection by the Arbitrum DAO.

Late quorum extension

An extension of the a Governance proposal's voting period by at most two days if Quorum is reached late, such that there are at least two days of voting after quorum is reached. With late-quorum extension logic, it follows that a proposal's voting period is at least 14 days and at most 16 days.

Layer 1 (L1)

The base protocol and underlying blockchain of the Ethereum network. Responsible for maintaining the integrity of the distributed ledger and executing smart contracts. Contains both Ethereum's execution layer and consensus layer.

Layer 2 (L2)

Trustless scaling solutions built on top of Ethereum's Layer 1 (L1) base protocol, such as state channels, plasma chains, optimistic rollups, and ZK-rollups. Layer 2 solutions aim to increase scalability and reduce the cost of transactions on Ethereum's Layer 1 without introducing additional trust assumptions.

Mechanism design

The process of designing protocols - or mechanisms - that incentivize specific behaviors. Within the context of Ethereum, mechanism design usually refers to mechanisms that attempt to align the incentives of participants in order to achieve particular outcomes in a fair and transparent manner. Developers use Arbitrum to implement mechanism designs within their Decentralized apps (dApps).

Multisignature wallet

A wallet that requires multiple private keys to sign transactions. Used by the Security Council to trigger Emergency actions. Commonly referred to as "multi-sig wallets".

Node operator

Anyone who runs core protocol software in the Ethereum / Arbitrum ecosystem; e.g., Ethereum Nodes, Arbitrum One nodes, or Arbitrum Nova nodes.

Non-constitutional AIP

One of two types of Arbitrum DAO Governance proposals (the other being Constitutional AIP). Non-constitutional AIPs are those that don't meet the criteria to be considered "constitutional".

Non-emergency action

Routine actions taken by the Security Council, such as software upgrades and maintenance. Emergency actions are activated only after a delay, as opposed to Emergency action.

Off-chain governance

As opposed to on-chain governance or Smart contract governance. Off-chain governance is carried out through social consensus, and off-chain proposals. The Ethereum Foundation's EIP mechanism is an example of an off-chain governance protocol.

Off-chain governance action

One of two types of governance actions allowed by The Constitution of the Arbitrum DAO. Off-chain actions are actions that are executed without Smart contracts. An example of an off-chain governance action is taking a "temperature check" on a proposal before submitting it to the governor contract.

On-chain governance

As opposed to off-chain governance, social governance, or pseudo governance. On-chain governance is governance implemented by Smart contracts that allow DAO members to determine - through the use of Governance proposals - how the DAO allocates its resources and updates its protocols. The Arbitrum DAO utilizes on-chain governance.

On-chain governance action

One of two types of governance actions allowed by The Constitution of the Arbitrum DAO. On-chain actions are executed as transactions submitted to the Arbitrum DAO's governance smart contracts. Updating the rate of $ARB inflation is an example of an on-chain governance action.

Optimistic rollup protocol

Optimistic rollup protocols are Layer 2 (L2) protocols that are designed to extend the throughput of Ethereum's base layer by using the base later for data availability and offloading computation to off-chain nodes. Arbitrum Rollup Protocol is an optimistic rollup protocol that inherits Ethereum's base-layer security guarantees.

Parent chain

EVM compatible chain that acts as the settlement layer for one or more Arbitrum Chains (aka Child chain ). E.g., Ethereum is the parent chain of both Arbitrum One and Arbitrum Nova. Parent chain is synonymous with "underlying chain."

Progressive decentralization

The process of gradually increasing the decentralization of a system over time. In the context of the Arbitrum DAO, and decentralizing Arbitrum One and Arbitrum Nova, progressive decentralization refers to decentralizing the ownership of the chains, validators, sequencers, and the Data Availability Committee (DAC).

Proposal waiting period

A contract-enforced delay period of roughly two weeks that begins after a Governance proposal is accepted, and after which the proposal takes effect. The proposal waiting period is intended to give users the option of opting out (for example, by withdrawing their funds).


A consensus-layer client that powers Ethereum Layer 1 (L1). Originally created by Prysmatic Labs; acquired by Offchain Labs in 2022.


Minimum votes required for a Governance proposal to pass. For each governor's proposals, the quorum is a percentage of the non-excluded votes at the time that voting on the proposal begins (5% for the Core Governor and 3% for the Treasury Governor.

Security Council

A 12-member council of entities who hold the private keys to a 12-member Multisignature wallet. Members of the council use this wallet to perform Emergency actions and Non-emergency actions.

Security Council Cohort

The 12 members of the Security Council are split into two six-member cohorts; during a Security Council election, the six seats in one the two cohorts seats are up election.

Security Council election

A process by which the Arbitrum DAO can elect the members of the Security Council. Happens twice a year.

Security Council Election Compliance

Second phase of a Security Council election, in which The Arbitrum Foundation ensures nominees have passed the requisite compliance checks in order to become Security Council members.

Security Council Member Selection

Final phase of a Security Council election, after which the six nominees who received the most votes become members of the Security Council.

Security Council Nominee Selection

First phase of a Security Council election, in which candidates who meet a minimum threshold of votes advance.

Seed phrase

Also referred to as "recovery phrase" or "backup phrase". A highly sensitive, deterministic sequence of words that you can use to recover your Ethereum wallet's private keys if you lose your credentials or device.


An entity (currently a single-party on Arbitrum One) given rights to reorder transactions in the Fast Inbox over a fixed window of time, who can thus give clients sub-blocktime Soft Confirmations. (Not to be confused with a Validator).

Smart contract

Self-executing code that's stored and executed on the Ethereum blockchain - either on Layer 1 (L1) or Layer 2 (L2). Smart contracts let you automate tasks and protocols in a Trustless manner. The Arbitrum DAO uses smart contracts to trustlessly implement the protocol defined by The Constitution of the Arbitrum DAO.

Snapshot poll

Mechanism by which Delegates can vote off-chain; used for temperature checks in conjunction with the Arbitrum DAO governance forum.

Standard Token gateway

A series of smart contracts responsible for bridging ERC20 tokens on Ethereum to Arbitrum chains like Arbitrum One or Arbitrum Nova and back. The standard gateway keeps the L1 token escrowed on Ethereum and mints/burns the L2 token representation upon deposits/withdrawals.


Web interface that can be used to interact with Arbitrum Governance contracts, including viewing, submitting, and voting on Governance proposals. Link

The Arbitrum Foundation

A legal entity that is governed by the Arbitrum DAO. Is bound to the rules articulated within The Constitution of the Arbitrum DAO.

The Arbitrum Treasury tokens

$ARB tokens owned by the Arbitrum DAO Treasury.

The Constitution of the Arbitrum DAO

A formal document that lays out the rules, procedures, and community values by which the Arbitrum DAO operates. The hash of the canonical constitution is stored on chain and is updatable via governance. The protocol outlined by The Constitution of the Arbitrum DAO is codified within the Smart contracts that facilitate Arbitrum DAO governance.

Timelock contract

A smart contract that restricts an action from taking place before a specified future time. Used at various stages in the Arbitrum DAO's governance proposal process.

Token Distributor Contract

Smart contract that was responsible for holding and distributing $ARB tokens for the Airdrop. The airdrop ended 9/24/23.

Token-weighted governance

A protocol governance system in which voting weight is proportional to ownership of a governance token. The Arbitrum DAO implements token-weighted governance.

Transparency report

A report that explains what actions were taken and why, especially after Emergency actions executed by the Security Council.

Treasury Governor

Governance contract responsible for creating Non-constitutional AIPs, or "treasury proposals", e.g., transferring founds out of the Arbitrum DAO Treasury.


In the context of Ethereum, trustless refers to the ability of a system to operate without reliance on a central authority or intermediary. Instead, users place their trust in math and protocols.

This is achieved through the use of cryptographic techniques and decentralized consensus mechanisms that let users verify the integrity of network transactions using open-source software. Trustless systems are considered to be more secure and resistant to fraud or tampering because they don't rely on a single point of failure that can be exploited by attackers.

Unclaimed airdrop tokens

Claimable $ARB tokens in the Token Distributor Contract not claimed by their potential owners. Unclaimed airdrop tokens were [transferred]( to the DAO Treasury after the airdrop ended.

Votable tokens

All $ARB tokens in existence except for:

Votable tokens give their holders voting power in direct proportion to the quantity of tokens held. More $ARB == more voting power.

Voting period

14-16 days after an Arbitrum Improvement Proposal (AIP) is successfully submitted during which members of the Arbitrum DAO can vote for or against.