Merge pull request #505 from OffchainLabs/glossary-updates

Glossary updates: stylus things, parent/child chain nomenclature

arbitrum-docs/partials/_glossary-partial.md

@@ -7,7 +7,7 @@
 <p>An address deterministically generated from an L1 contract address used on L2 to safely identify the source of an L1 to L2 message.</p>
 
 ### Arb Token Bridge {#arb-token-bridge}
-<p>A series of contracts on Ethereum and Arbitrum that facilitate trustless movement of ERC-20 tokens between L1 and L2.</p>
+<p>A series of contracts on an Arbitrum chain and its underlying chain that facilitate trustless movement of ERC-20 tokens between the two layers.</p>
 
 ### Arbitrum {#arbitrum}
 <p>A suite of Ethereum layer-2 scaling technologies built with the <a href="/intro/glossary#arbitrum-nitro">Arbitrum Nitro</a> tech stack that includes <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> (a live implementation of the <a href="/intro/glossary#arbitrum-rollup-protocol">Arbitrum Rollup Protocol</a>) and <a href="/intro/glossary#arbitrum-nova">Arbitrum Nova</a> (a live implementation of the <a href="/intro/glossary#arbitrum-anytrust-protocol">Arbitrum AnyTrust Protocol</a>).</p>
@@ -19,7 +19,7 @@
 <p>An Arbitrum protocol that manages data availability with a permissioned set of parties known as the <a href="/intro/glossary#data-availability-committee-dac">Data Availability Committee (DAC)</a>. This protocol reduces transaction fees by introducing an additional trust assumption for data availability in lieu of Ethereum's <a href="/intro/glossary#trustless">Trustless</a> data availability mechanism. <a href="/intro/glossary#arbitrum-nova">Arbitrum Nova</a> is an example of an AnyTrust chain; <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> is an alternative chain that implements the purely trustless (and more L1-gas intensive) <a href="/intro/glossary#arbitrum-rollup-protocol">Arbitrum Rollup Protocol</a>.</p>
 
 ### Arbitrum chain {#arbitrum-chain}
-<p>A blockchain that runs on the Arbitrum protocol. Arbitrum chains are EVM compatible, and use an underlying L1 (Ethereum) for settlement and for succinct fraud-proofs (as needed).  Arbitrum chains come in two forms: <a href="/intro/glossary#arbitrum-rollup-chain">Arbitrum Rollup Chain</a>s and <a href="/intro/glossary#arbitrum-anytrust-chain">Arbitrum AnyTrust Chain</a>s. </p>
+<p>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: <a href="/intro/glossary#arbitrum-rollup-chain">Arbitrum Rollup Chain</a>s and <a href="/intro/glossary#arbitrum-anytrust-chain">Arbitrum AnyTrust Chain</a>s. </p>
 
 ### Arbitrum Classic {#arbitrum-classic}
 <p><a href="https://github.com/OffchainLabs/arbitrum">Old Arbitrum stack</a> that used custom virtual machine ("AVM"); no public Arbitrum chain uses the classic stack as of 8/31/2022 (they instead use <a href="/intro/glossary#arbitrum-nitro">Arbitrum Nitro</a> ).</p>
@@ -28,7 +28,7 @@
 <p>A party who keeps track of the state of an Arbitrum chain and receives remote procedure calls (RPCs) from clients. Analogous to a non-staking L1 Ethereum node.</p>
 
 ### Arbitrum Nitro {#arbitrum-nitro}
-<p>Current Arbitrum tech stack; runs a fork of <a href="/intro/glossary#geth">Geth</a> directly on <a href="/intro/glossary#layer-2-l2">Layer 2 (L2)</a> and uses WebAssembly as its underlying VM for fraud proofs.</p>
+<p>Current Arbitrum tech stack; runs a fork of <a href="/intro/glossary#geth">Geth</a> and uses WebAssembly as its underlying VM for fraud proofs.</p>
 
 ### Arbitrum Nova {#arbitrum-nova}
 <p>The first <a href="/intro/glossary#arbitrum-anytrust-chain">Arbitrum AnyTrust Chain</a> running on Ethereum mainnet. Introduces cheaper transactions; great for gaming and social use-cases. Implements the <a href="/intro/glossary#arbitrum-anytrust-protocol">Arbitrum AnyTrust Protocol</a>, not the <a href="/intro/glossary#arbitrum-rollup-protocol">Arbitrum Rollup Protocol</a> protocol. </p>
@@ -43,16 +43,16 @@
 <p>An <a href="/intro/glossary#arbitrum-chain">Arbitrum chain</a> that implements the <a href="/intro/glossary#arbitrum-rollup-protocol">Arbitrum Rollup Protocol</a>.</p>
 
 ### Arbitrum Rollup Protocol {#arbitrum-rollup-protocol}
-<p>A trustless, permissionless Arbitrum <a href="/intro/glossary#layer-2-l2">Layer 2 (L2)</a> protocol that uses its underlying base layer (i.e., Ethereum) for data availability and inherits its security. This protocol is implemented by our <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> chain. </p>
+<p>A trustless, permissionless Arbitrum protocol that uses its underlying base layer for data availability and inherits its security. This protocol is implemented by our <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> chain. </p>
 
 ### ArbOS {#arbos}
-<p>Layer 2 "operating system" that trustlessly handles system-level operations; includes the ability to emulate the EVM.</p>
+<p>Arbitrum's "operating system" that trustlessly handles system-level operations; includes the ability to emulate the EVM.</p>
 
 ### Assertion {#assertion}
 <p>A staked claim by an Arbitrum <a href="/intro/glossary#validator">Validator</a>. An assertion may, e.g., propose a new <a href="/intro/glossary#rblock">RBlock</a>, or may be a step in a <a href="/intro/glossary#challenge">Challenge</a>.</p>
 
 ### Batch {#batch}
-<p>A group of L2 transactions posted in a single L1 transaction into the <a href="/intro/glossary#fast-inbox">Fast Inbox</a>  by the <a href="/intro/glossary#sequencer">Sequencer</a>.</p>
+<p>A group of Arbitrum transactions posted in a single transaction on the <a href="/intro/glossary#underlying-chain">Underlying Chain</a>  into the <a href="/intro/glossary#fast-inbox">Fast Inbox</a>  by the <a href="/intro/glossary#sequencer">Sequencer</a>.</p>
 
 ### Blockchain {#blockchain}
 <p>A distributed digital ledger that is used to record transactions and store data in a secure, transparent, and tamper-resistant way, notably in cryptocurrency protocols. </p>
@@ -66,14 +66,17 @@
 <p>A particular point in the history of an <a href="/intro/glossary#arbitrum-chain">Arbitrum chain</a>. A chain's state is determined by applying Arbitrum state-transition function to sequence of transactions (i.e., the chain's history).</p>
 
 ### Challenge {#challenge}
-<p>When two <a href="/intro/glossary#staker">Staker</a>s disagree about the correct verdict on an <a href="/intro/glossary#assertion">Assertion</a>, those stakers can be put in a challenge. The challenge is refereed by the contracts on L1. Eventually one staker wins the challenge. The protocol guarantees that an honest  party will always win a challenge; the loser forfeits their stake. </p>
+<p>When two <a href="/intro/glossary#staker">Staker</a>s disagree about the correct verdict on an <a href="/intro/glossary#assertion">Assertion</a>, those stakers can be put in a challenge. The challenge is refereed by the contracts on the underlying chain. Eventually one staker wins the challenge. The protocol guarantees that an honest  party will always win a challenge; the loser forfeits their stake. </p>
 
 ### Challenge Period {#challenge-period}
 <p>Window of time (1 week on Arbitrum One) over which an asserted <a href="/intro/glossary#rblock">RBlock</a>  can be challenged, and after which the RBlock can be confirmed.</p>
 
 ### Challenge protocol {#challenge-protocol}
 <p>The protocol by which <a href="/intro/glossary#rblock">RBlock</a>s are submitted, disputed, and ultimately confirmed. The Challenge Protocol guarantees that only valid RBlocks will be confirmed provided that there is at least one honest <a href="/intro/glossary#active-validator">Active Validator</a>.</p>
 
+### Child chain {#child-chain}
+<p>An Arbitrum Chain that settles to an underlying <a href="/intro/glossary#parent-chain">Parent chain</a> . For example, Arbitrum One and Arbitrum Nova are child chains of Ethereum.</p>
+
 ### Client {#client}
 <p>A program running on a user's machine, often in the user's browser, that interacts with contracts on an <a href="/intro/glossary#arbitrum-chain">Arbitrum chain</a>  and provides a user interface.</p>
 
@@ -106,7 +109,7 @@
 <p>A <a href="/intro/glossary#validator">Validator</a> that watches an Arbitrum chain and takes action (i.e., stakes and challenges) only when and if an invalid <a href="/intro/glossary#assertion">Assertion</a> occurs.</p>
 
 ### Delayed Inbox {#delayed-inbox}
-<p>A contract that holds L1 initiated messages to be eventually included in the <a href="/intro/glossary#fast-inbox">Fast Inbox</a>. Inclusion of messages doesn't depend on the <a href="/intro/glossary#sequencer">Sequencer</a>.</p>
+<p>A contract that holds <a href="/intro/glossary#parent-chain">Parent chain</a> initiated messages to be eventually included in the <a href="/intro/glossary#fast-inbox">Fast Inbox</a>. Inclusion of messages doesn't depend on the <a href="/intro/glossary#sequencer">Sequencer</a>.</p>
 
 ### Dissection {#dissection}
 <p>A step in the <a href="/intro/glossary#challenge-protocol">Challenge protocol</a>  in which two challenging parties interactively narrow down their disagreement until they reach a <a href="/intro/glossary#one-step-proof">One Step Proof</a>.</p>
@@ -129,7 +132,7 @@ Commonly associated with the esteemed Diamond Pepe's NFT and Dopex community. Do
 <p>Contract that holds a sequence of messages sent by clients to an Arbitrum Chain; a message can be put into the fast Inbox directly by the <a href="/intro/glossary#sequencer">Sequencer</a>  or indirectly through the <a href="/intro/glossary#delayed-inbox">Delayed Inbox</a>.</p>
 
 ### Force-Inclusion {#forceinclusion}
-<p>Censorship resistant path for including a message into L2 via the <a href="/intro/glossary#delayed-inbox">Delayed Inbox</a>; bypasses any Sequencer involvement.</p>
+<p>Censorship resistant path for including a message into an Arbitrum chain via the <a href="/intro/glossary#delayed-inbox">Delayed Inbox</a> on its <a href="/intro/glossary#parent-chain">Parent chain</a>; bypasses any Sequencer involvement.</p>
 
 ### Fraud proof {#fraud-proof}
 <p>The means by which an <a href="/intro/glossary#active-validator">Active Validator</a> proves to its underlying chain that an invalid state transition has taken place.</p>
@@ -167,11 +170,14 @@ The iconic blueberries come from the community of the decentralized exchange, GM
 <p>An Arbitrum chain whose core contract reside on an  Arbitrum <a href="/intro/glossary#layer-2-l2">Layer 2 (L2)</a> chain.</p>
 
 ### One Step Proof {#one-step-proof}
-<p>Final step in a challenge; a single operation of the L2 VM (Wasm) is executed on L1, and the validity of its state transition is verified.</p>
+<p>Final step in a challenge; a single operation of the Arbitrum VM (<a href="/intro/glossary#wasm">WASM</a> ) is executed on the underlying chain, and the validity of its state transition is verified.</p>
 
 ### Outbox {#outbox}
 <p>An L1 contract responsible for tracking <a href="/intro/glossary#l2-to-l1-message">L2 to L1 Message</a>s, including withdrawals, which can be executed once they are confirmed. The outbox stores a Merkle Root of all outgoing messages.</p>
 
+### Parent chain {#parent-chain}
+<p>EVM compatible chain that acts as the settlement layer for one or more Arbitrum Chains (aka <a href="/intro/glossary#child-chain">Child chain</a>  ). E.g., Ethereum is the parent chain of both Arbitrum One and Arbitrum Nova. Parent chain is synonymous with "underlying chain." </p>
+
 ### 🏴‍☠️ Pirate Nation {#pirate-nation}
 <p>If you sail in the deep blue seas of Arbitrum, you may encounter some ships with pirate flags along the way ARRGG!<br />
 <br />
@@ -190,7 +196,7 @@ The pirate flag originates from the Pirate Nation community. Pirate Nation is a
 <p>An L1 to L2 cross chain message initiated by an L1 transaction sent to an Arbitrum chain for execution (e.g., a token deposit).</p>
 
 ### Reverse Token Gateway {#reverse-token-gateway}
-<p>A <a href="/intro/glossary#token-gateway">Token Gateway</a> in which the L2 Gateway contract escrows and releases tokens, which the L1 Gateway contract mints and burns tokens. This in the inverse to how "typical" gateways work.</p>
+<p>A <a href="/intro/glossary#token-gateway">Token Gateway</a> in which the <a href="/intro/glossary#child-chain">Child chain</a> gateway contract escrows and releases tokens, which the <a href="/intro/glossary#parent-chain">Parent chain</a> Gateway contract mints and burns tokens. This in the inverse to how "typical" gateways work.</p>
 
 ### Sequencer {#sequencer}
 <p>An entity (currently a single-party on Arbitrum One) given rights to reorder transactions in the <a href="/intro/glossary#fast-inbox">Fast Inbox</a>  over a fixed window of time, who can thus give clients sub-blocktime <a href="/intro/glossary#soft-confirmation">Soft Confirmation</a>s. (Not to be confused with a <a href="/intro/glossary#validator">Validator</a>).</p>
@@ -207,22 +213,22 @@ The pirate flag originates from the Pirate Nation community. Pirate Nation is a
 If you see any Smol's with giga brains, swole arms or hear the sound of "EEEE" in the Arbitrum community, you've encountered the Smol Brains and Smol Bodies. </p>
 
 ### Soft Confirmation {#soft-confirmation}
-<p>A semi-trusted promise from the <a href="/intro/glossary#sequencer">Sequencer</a>  to post a user's transaction in the near future; soft-confirmations happen prior to posting on L1, and thus can be given near-instantaneously (i.e., faster than L1 block times)</p>
+<p>A semi-trusted promise from the <a href="/intro/glossary#sequencer">Sequencer</a>  to post a user's transaction in the near future; soft-confirmations happen prior to posting on the <a href="/intro/glossary#parent-chain">Parent chain</a>, and thus can be given near-instantaneously (i.e., faster than the parent chain's block times)</p>
 
 ### Speed Limit {#speed-limit}
-<p>Target L2 computation limit for an Arbitrum chain. <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> and <a href="/intro/glossary#arbitrum-nova">Arbitrum Nova</a>  currently target 7,000,000 gas / second. When computation exceeds this limit, fees rise, ala <a href="https://notes.ethereum.org/@vbuterin/eip-1559-faq">EIP-1559</a>.</p>
+<p>Target computation limit for an Arbitrum chain. <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> and <a href="/intro/glossary#arbitrum-nova">Arbitrum Nova</a>  currently target 7,000,000 gas / second. When computation exceeds this limit, fees rise, ala <a href="https://notes.ethereum.org/@vbuterin/eip-1559-faq">EIP-1559</a>.</p>
 
 ### Staker {#staker}
 <p>A <a href="/intro/glossary#validator">Validator</a> who deposits a stake (in Ether on <a href="/intro/glossary#arbitrum-one">Arbitrum One</a> and <a href="/intro/glossary#arbitrum-nova">Arbitrum Nova</a> ) to vouch for a particular <a href="/intro/glossary#rblock">RBlock</a>  in an Arbitrum Chain. A validator who stakes on a false RBlock can expect to lose their stake. An honest staker can recover their stake once the RBlock they are staked on has been confirmed.</p>
 
 ### Standard Arb-Token {#standard-arbtoken}
-<p>An L2 token contract deployed via the <a href="/intro/glossary#standarderc20-gateway">StandardERC20 gateway</a>; offers basic ERC20 functionality in addition to deposit / withdrawal affordances.</p>
+<p>An token contract on an Arbitrum chain deployed via the <a href="/intro/glossary#standarderc20-gateway">StandardERC20 gateway</a>; offers basic ERC20 functionality in addition to deposit / withdrawal affordances.</p>
 
 ### StandardERC20 gateway {#standarderc20-gateway}
-<p><a href="/intro/glossary#token-gateway">Token Gateway</a> via which any L1 ERC20 token can permissionlessly bridge; the StandrardERC20 gateway contracts deploy a <a href="/intro/glossary#standard-arbtoken">Standard Arb-Token</a> on L2 for each bridged token.</p>
+<p><a href="/intro/glossary#token-gateway">Token Gateway</a> via which any underlying chain's ERC20 token can permissionlessly bridge; the StandrardERC20 gateway contracts deploy a <a href="/intro/glossary#standard-arbtoken">Standard Arb-Token</a> on the <a href="/intro/glossary#child-chain">Child chain</a>   for each bridged token.</p>
 
 ### Stylus {#stylus}
-<p>Upcoming upgrade to the <a href="/intro/glossary#arbitrum-nitro">Arbitrum Nitro</a> virtual machine that will allow smart contract support for languages like Rust and C++ by taking advantage of Nitro's use of WASM (<a href="https://offchain.medium.com/hello-stylus-6b18fecc3a22">read more</a>).</p>
+<p>Upgrade to the <a href="/intro/glossary#arbitrum-nitro">Arbitrum Nitro</a> virtual machine that allows smart contract support for languages like Rust and C++ by taking advantage of Nitro's use of WASM. Currently on testnet (<a href="https://docs.arbitrum.io/stylus/stylus-gentle-introduction">read more</a>).</p>
 
 ### 🏹 Tales of Elleria {#tales-of-elleria}
 <p>The bow and arrow are commonly associated with the Hero's of Tales of Elleria.<br />
@@ -236,7 +242,7 @@ The iconic Toads of Arbitrum love to hunt BUGZ <br />
  and collect NFTs. !CROAK</p>
 
 ### Token Gateway {#token-gateway}
-<p>A pair of contracts in the token bridge — one on L1, one on L2 — that provide a particular mechanism for handling the transfer of tokens between layers. Token gateways currently active in the bridge include the <a href="/intro/glossary#standarderc20-gateway">StandardERC20 gateway</a> , the <a href="/intro/glossary#genericcustom-gateway">Generic-Custom Gateway</a> , and the <a href="/intro/glossary#weth-gateway">WETH Gateway</a>.</p>
+<p>A pair of contracts in the token bridge — one on the <a href="/intro/glossary#parent-chain">Parent chain</a>  , one on the <a href="/intro/glossary#child-chain">Child chain</a>  — that provide a particular mechanism for handling the transfer of tokens between layers. Token gateways currently active in the bridge include the <a href="/intro/glossary#standarderc20-gateway">StandardERC20 gateway</a> , the <a href="/intro/glossary#genericcustom-gateway">Generic-Custom Gateway</a> , and the <a href="/intro/glossary#weth-gateway">WETH Gateway</a>.</p>
 
 ### 🏡 TownStory  {#townstory-}
 <p>If you see some homes along your road trip in the Arbitrum ecosystem, you've made it to TownStory.<br />
@@ -260,9 +266,15 @@ This is achieved through the use of cryptographic techniques and decentralized c
 
 
 
+### Underlying Chain {#underlying-chain}
+<p>Synonymous with <a href="/intro/glossary#parent-chain">Parent chain</a>.</p>
+
 ### Validator {#validator}
 <p>An <a href="/intro/glossary#arbitrum-full-node">Arbitrum Full Node</a> that tracks the status of the chains' <a href="/intro/glossary#assertion">Assertion</a>s. A validator may be a <a href="/intro/glossary#watchtower-validator">Watchtower Validator</a>, a <a href="/intro/glossary#defensive-validator">Defensive Validator</a>, or an <a href="/intro/glossary#active-validator">Active Validator</a>. </p>
 
+### WASM {#wasm}
+<p>Widely supported binary code format for executable programs. Used by <a href="/intro/glossary#arbitrum-nitro">Arbitrum Nitro</a> for  <a href="/intro/glossary#fraud-proof">Fraud proof</a>s , and more broadly used by <a href="/intro/glossary#stylus">Stylus</a> to support performant smart contracts in a wide variety of languages.</p>
+
 ### Watchtower Validator {#watchtower-validator}
 <p>A <a href="/intro/glossary#validator">Validator</a>  that never stakes / never takes on chain action, who raises the alarm (by whatever off-chain means it chooses) if it witnesses an invalid assertion.</p>