- ComposabilityThe ability for applications on a blockchain to read and write state to each other.
- ConsensusA function of modular blockchains where the ordering of transactions is agreed upon by a set of validators.
- Consensus algorithmA consensus algorithm is a set of rules that blockchains use to determine how nodes produce new blocks and agree to finalize them.
- Consensus layerA modular blockchain that provides transaction ordering for other modular blockchains, like rollups.
- Cosmos SDKThe Cosmos SDK is a development kit for building PoS layer 1 blockchains with Tendermint as the consensus mechanism.
- Cross-chain interoperabilityThe ability for separate blockchains to communicate and interact with each other.
- DADA stands for Data Availability.
- DACDAC stands for Data Availability Committee.
- DASDAS stands for Data Availability Sampling.
- Data availability samplingA technique in which nodes can verify that data is available for a block without having to download the entire block, formerly known as data availability proofs.
- Data availabilityThe condition of whether or not transaction data was made available for nodes to download, when a block was proposed.
- Data availability committeeA data availability committee (DAC) is a permissioned group of nodes responsible for providing data availability to a blockchain.
- Data availability layerA blockchain that provides for other types of chains, like rollups.
- Data throughputA measurement of the data capacity of a blockchain. Data throughput is calculated by the amount of data that a blockchain can process, measured in kb/s or mb/s.
- Data withholding attackA type of attack that occurs when a block producer proposes a new block but does not share the underlying transaction data that was used to create the block.
- Dispute resolutionThe handling and resolution of disputes, commonly used as a term in relation to optimistic rollups and their fraud proof mechanism.
- EEEE stands for Execution Environment.
- ExecutionA function of modular blockchains where transactions are executed and the new state of the chain is determined.
- Execution environmentThe virtual environment within a blockchain where transactions are processed, and accounts and smart contracts live.
- Execution layerA type of modular blockchain whose primary job is hosting smart contracts and executing transactions.
- Fee marketA type of market that blockchains implement to prevent malicious actors from spamming the network.
- ForkA software upgrade that causes the blockchain to split into two chains that may or may not be compatible with each other.
- Fork choice ruleAn algorithm that nodes use to correctly identify and follow the canonical chain.
- Full nodeA type of node that fully verifies a blockchain.
- Light clientA type of node that only downloads and verifies block headers, relying on an honest majority assumption that the state of the chain indicated by the block header is valid.
- Light nodeIn Celestia, a light node is a type of node that verifies block headers and does data availability sampling.
- LivenessLiveness is a property of blockchains where validators produce new blocks and successfully finalize transactions.
- Namespaced Merkle TreeA Namespaced Merkle Tree (NMT) is a type of binary Merkle tree where each node in the tree is tagged by the minimum and maximum namespace of their children.
- NMTNMT stands for Namespaced Merkle Tree.
- NodeA node is a device that participates in a blockchain protocol by running its software.
- Off-chain data availabilityOff-chain data availability occurs when an L2 publishes its transaction data somewhere separate from the L1 it settles on.
- On-chain data availabilityOn-chain data availability occurs when an L2 publishes its transaction data to its designated L1.
- Optimistic rollupA type of rollup that posts its blocks to a separate chain without any cryptographic proofs that attest to their validity.
- ORUORU stands for Optimistic Rollup.
- Peer to peer networkA network in which nodes are connected and can communicate directly with each other without reliance on a third party to facilitate communication.
- PFBPFB stands for PayforBlob.
- Proof of StakeProof of Stake is a mechanism that requires blockchain participants to stake a token to participate in consensus.
- SafetySafety is a property of blockchains that a chain will not fork.
- ScalabilityScalability is the ability of a blockchain to increase its capacity without an equal increase in the cost to run a node that verifies the chain.
- SettlementA function of modular blockchains where transaction proofs from rollups are verified and disputes are resolved.
- Settlement layerA modular blockchain whose primary role is to provide proof verification and dispute resolution for rollups.
- SequencerA sequencer is a type of rollup node that is responsible for collecting transactions and producing new blocks.
- ShardingThe process of separating a blockchain from a single chain into multiple chains (shards).
- Shared securitySecurity that a blockchain inherits from an external source.
- SlashingA mechanism employed in PoS blockchains that is used to deter and punish malicious behavior.
- Smart contractA smart contract is a program that runs on a blockchain.
- Social consensusThe process by which individuals come to an agreement on a change that will be made to a blockchain.
- Sovereign applicationAn application that is deployed on its own sovereign blockchain.
- Sovereign blockchainA blockchain that has independent control over itself and its applications via social consensus.
- Sovereign rollupA type of rollup that does not use a settlement layer to determine its canonical chain and validity rules.
- State transition fraud proofA method for proving that a state transition is invalid.
- Synchrony assumptionAn assumption that the network is synchronous such that when a message is sent it will be received within a certain amount of time.
- ThroughputA measurement of the capacity of a blockchain. Throughput primarily measures two elements: data throughput and transaction throughput.
- The data availability problemA problem that is concerned with whether the data in the proposed block can be verified that it is available.
- Transaction throughputThe computational capacity of a blockchain. Transaction throughput is commonly calculated by the number of transactions that can be processed per second (TPS).
- Trust minimized bridgeA bridge between two blockchains that doesn’t require an intermediary, a committee, or an honest majority assumption to ensure that funds can’t be stolen.
- Trusted bridgeA bridge between two blockchains that requires either a trusted intermediary, committee, or an honest majority assumption to ensure that funds can’t be stolen.
- ValidatorA full node that is part of the validator set in a PoS blockchain.
- Validator setA group of validators that are responsible for directly participating in the consensus of a blockchain through either voting, producing, or proposing blocks.
- Validity proofA type of cryptographic proof that can be used to attest to the validity of a state transition.
- ValidiumA type of zero-knowledge rollup that posts its data off-chain rather than to its parent chain.
- VolitionA zero-knowledge rollup with options for both on-chain and off-chain data availability.