Glossary

A dedicated blockchain built for a specific application or limited set of tasks. Unlike general-purpose blockchains, appchains are optimized for their use case and can include tailored performance, security, or governance features, for example in areas like gaming or decentralized finance (DeFi).

Typically refers to user-facing programs indirectly interacting with the Cardano blockchain to deliver specific services to end-users. It is usually distinguished from the infrastructure layer (a.k.a middleware) that comprises programs that interact directly with blockchain nodes to provide higher-level interfaces for the application layer.

The architecture of Cardano is organized into several components that comprise key functions of the blockchain. These include the networking layer for peer-to-peer communication, a consensus layer based on the Ouroboros protocol, a settlement layer that records transactions, and a scripting layer that enables smart contracts and dApps.

An asset is any unit of value that can be recorded, transferred, or managed using the blockchain infrastructure and associated tools. On Cardano, assets can be ada (the native token) or other native tokens (Cardano Native Tokens; CNT). Blockchain assets are a form of digital assets, whereas digital assets generally comprise any item of value that exists in digital form and can be owned or transferred electronically.

Refers to the process of creating digital tokens on a blockchain that represent ownership, rights, or claims to an underlying (real -world) asset. These assets can be tangible, such as real estate or commodities, or intangible, such as intellectual property or financial instruments.

An automated transaction method in which a token exchange between parties using a blockchain either executes in full under predefined conditions or is cancelled entirely. This all-or-nothing design eliminates counterparty risk for a transaction and prevents partial exchanges.

Refers to the verifiable and tamper-proof nature of data stored on a blockchain, ensuring that the data is genuine, trustworthy, and has not been altered or falsified.

The second phase in Cardano's development roadmap focused on decentralization and smart contract capabilities.

A type of Cardano wallet that displays the total ada or token balance as a single figure, rather than showing the individual unspent transaction outputs (UTXOs) that make up that balance. It simplifies the UTXO model for end users by abstracting the technical details of how funds are structured on the blockchain.

The fourth phase in Cardano's development roadmap focused on scalability and optimization. The Basho era enhanced the network's throughput and efficiency with functionality like sharding and sidechains. Named after Matsuo Basho, a Japanese poet and haiku master.

A block is a structured set of data that records validated transactions and links to the previous block in the chain. Each block contains a cryptographic reference (hash) to the prior block, ensuring the integrity and chronological order of the blockchain ledger.

A distributed digital ledger that records transactions in a sequence of linked blocks, secured through cryptography and agreed upon by a network of participants. Its design makes records transparent, tamper-resistant, and verifiable.

A model where third-party providers offer blockchain infrastructure, tools, and services, usually through a cloud-based platform. It allows businesses and developers to deploy, manage, and use blockchain applications without operating their own nodes or maintaining the underlying network.

A collaborative group of organizations that come together to jointly operate and govern a blockchain. The consortium defines membership, governance rules, and shared objectives for the use of the system.

An online tool that allows users to view and search blockchain data, such as transactions, addresses, block details, and network statistics. For Cardano, a list of explorers can be found at https://explorer.cardano.org.

Refers to software that acts as a bridge between blockchain protocols and applications, simplifying interaction with the underlying network. It can provide services such as data indexing, APIs, identity management, or integration tools, enabling developers and organizations to build on blockchain infrastructure more efficiently.

The idea that a blockchain system can optimize for only two out of three key properties—decentralization, security, and scalability—at the same time. Balancing these three factors is a central challenge in blockchain design, with different protocols prioritizing them in different ways.

Refers to the number of blocks between the current block and the very first block. It serves as a sequential identifier that shows a block’s position in the chain and is often used to track progress, reference specific blocks, or measure network activity.

The compensation given to participants who produce or validate a new block on a blockchain. On Cardano, block rewards are distributed to stake pool operators and delegators in ada, providing incentives for securing the network under the proof-of-stake protocol.

Refers to systems that connect two different blockchains, enabling the transfer of assets or data between them. They work by locking or recording tokens on one chain and issuing a corresponding representation on the other, creating interoperability across otherwise separate networks.

The process of permanently removing tokens from circulation. The opposite of burning is minting, where new tokens are created.

The initial phase of Cardano's development that established core blockchain components such as the wallet infrastructure and consensus protocol, laying the groundwork for subsequent phases. Named after the Romantic poet who was the father of Ada Lovelace.

The ability of a distributed system to continue functioning correctly even if some participants act maliciously or fail to communicate honestly. In blockchains, BFT ensures that consensus can still be reached despite unreliable or compromised nodes.

A public, permissionless Layer 1 blockchain using a Proof-of-Stake (PoS) consensus mechanism. It is designed with a layered architecture and a research-driven approach, aiming to balance decentralization, security, and scalability while supporting smart contracts, native assets, and dApps.

An independent, Swiss-based not-for-profit organization with the main purpose of supporting the advancement of the Cardano blockchain as a public digital infrastructure. Its work focuses on adoption, education, and operational resilience. The Cardano Foundation is considered one of the pioneering entities, alongside IOG (formerly IOHK) and EMURGO, involved in the upbringing of the Cardano blockchain and its ecosystem.

A standardized process for suggesting and discussing changes or new features in the Cardano ecosystem. CIPs enable the community to review, debate, and adopt improvements in areas such as wallets, token standards, or governance.

A representative body within Project Catalyst, Cardano’s community-driven innovation fund. It acts as a communication and coordination forum between different stakeholder groups, highlighting issues, sharing feedback, and improving processes in the governance of the funding program.

Digital forms of a nation’s official currency, issued and controlled by its central bank. They combine the stability of traditional fiat money with the efficiency of digital payment systems, while remaining distinct from decentralized crypto assets like ada or bitcoin.

A trading platform operated by a central intermediary that allows users to buy, sell, and manage crypto assets. The operator usually manages custody of user funds, order matching, and regulatory compliance, making CEXs distinct from decentralized exchanges (DEXs) where users retain (more) control of their assets.

A component of hierarchical deterministic (HD) key generation used in wallets. Along with a cryptographic key, it enables the secure derivation of child keys from a parent key without exposing the parent private key, forming the basis for generating multiple addresses from a single seed phrase.

Refers to keeping private keys completely offline, away from internet-connected devices, to reduce the risk of theft or hacking. Common forms include hardware wallets, paper wallets, or other physical media stored securely.

Describes the shared agreement among network nodes about the current and valid state of the ledger. It is the outcome of the consensus mechanism, which coordinates nodes to validate transactions and produce new blocks in a consistent and secure manner.

The method a blockchain uses for participants to agree on the validity of transactions and the state of the ledger. Examples include proof of work (PoW) and proof of stake (PoS), with Cardano using the Ouroboros PoS protocol.

A consensus protocol is the set of rules and processes that govern how blockchain participants reach agreement on transactions and block production. Cardano’s consensus protocol is called Ouroboros, a family of proof-of-stake (PoS) protocols developed through peer-reviewed research.

A collaborative network where multiple organizations jointly operate and govern a shared blockchain. Unlike public, permissionless blockchains, consortium blockchains are permissioned, meaning access and participation are restricted to approved members.

The total amount of ada associated with a stake pool, including both the operator’s own pledge and the ada delegated by others. It represents the pool’s overall influence in the proof-of-stake consensus and determines its chance of producing blocks and earning rewards.

A development era of Cardano, introduced through the Chang hard fork, that establishes full decentralization and community-led governance. In this era, ada holders can directly vote on protocol changes and network decisions, marking the transition to a more inclusive and democratic blockchain system. Named after mathematician John Conway, it reflects the evolving and interconnected patterns of governance inspired by his Game of Life.

A parameter in Cardano’s staking system that defines the fixed fee a stake pool operator receives for producing blocks during each epoch. This fee is deducted from the pool’s total rewards before the remaining rewards are distributed to delegators.

COTI (Currency of the Internet) is a blockchain-based fintech platform that focuses on digital payments and stablecoin issuance. In the Cardano ecosystem, COTI is the issuer of the algorithmic stablecoin Djed, developed in collaboration with Input Output Global (IOG).

Refers to technology enabling interactions between different blockchain networks, allowing assets, data, or functionality to be transferred or shared across them. It comprises mechanisms such as bridges, sidechains, or standardized communication protocols.

A digital currency that uses cryptography to secure transactions and control the creation of new units. Most cryptocurrencies operate on blockchain networks.

Refers to the field of mathematics and computer science concerned with securing information through techniques like encryption, hashing, and digital signatures. In blockchains, cryptography ensures data integrity, protects private keys, and enables trustless transactions without relying on centralized authorities.

Refers to the responsibility for holding and safeguarding assets or funds. In the blockchain context, this can be done by the asset holder directly through managing their own private keys (self-custody) or delegated to a third party, such as an exchange or custodial service.

Daedalus is a full-node wallet for Cardano that downloads and independently verifies the entire blockchain. It gives users complete control over their ada, offering advanced features like running multiple wallets and increased security through full participation in the network.

The data layer of a blockchain is where all transactions and associated information are recorded on the ledger. It provides the foundation for transparency, immutability, and verifiability, serving as the base upon which higher protocol and application layers operate.

A piece of data attached to a transaction output in Cardano’s extended UTXO model. It provides information that smart contracts can use when validating whether the output can be spent, enabling more complex and programmable on-chain interactions.

Decentralization is the distribution of control and decision-making across many independent participants rather than relying on a single central authority. In blockchains, it is achieved through consensus mechanisms and the replication of the ledger across a distributed network of nodes, ensuring no single node can unilaterally control the system.

Refers to a software application that runs on a blockchain rather than a centralized server. It uses smart contracts to execute functions in a predefined way.

A blockchain-based governance structure where rules and decision-making are encoded in smart contracts. Token holders typically participate by proposing and voting on changes, enabling collective control over shared resources or projects.

A blockchain-based platform that allows users to trade crypto assets directly with one another without direct intermediaries. Transactions are usually facilitated by smart contracts, enabling users to retain control of their assets throughout the exchange process.

Refers to financial services built on blockchain networks that operate without traditional intermediaries such as banks or brokers.

A digital identity managed and controlled directly by its owner, rather than by a centralized authority. It relies on blockchain and cryptographic standards to enable secure, verifiable credentials while giving individuals greater privacy and control over their personal data.

A consensus mechanism where token holders vote to elect a smaller group of representatives to validate transactions and produce blocks on their behalf. This model increases efficiency and scalability but concentrates responsibility in the elected validators rather than distributing it across all participants.

Community members to whom ada holders can transfer their voting power in Cardano’s on-chain governance system. By delegating to a DRep, ada holders can participate indirectly in governance decisions, such as protocol updates and funding proposals, without having to vote on every issue themselves.

A delegate vote is the voting right that an ada holder assigns to a representative in Cardano’s governance system. It allows ada holders to participate in the network’s governance by voting on proposals and decisions related to protocol upgrades, funding distribution, and other matters, without needing to vote directly on each issue themselves.

Refers to the property of a system where the same inputs always produce the same outputs under the same conditions. In blockchains, this ensures that all nodes reach identical results when validating transactions or executing smart contracts, maintaining consistency across the distributed ledger.

The online representation of a person, organization, or device, made up of attributes and credentials that can be used for authentication or verification.

Describes systems for recording and sharing data across multiple computers, where each participant maintains a synchronized copy of the database (i.e. ledger). It enables transparency, security, and resilience by removing the need for a central authority, with blockchains being the most common type of DLT.

An algorithmic stablecoin built on the Cardano blockchain, designed to maintain a stable value by using smart contracts and reserve assets to balance supply and demand. It is issued by COTI in collaboration with Input Output Global (IOG) and aims to provide a stable medium of exchange within the Cardano ecosystem.

In the blockchain context, an ecosystem refers to the interconnected community of participants, technologies, and applications that develop and interact around a blockchain network. This includes developers, users, businesses, infrastructure providers, and governance structures that together support the network’s growth and utility. Such ecosystems are typically diverse, made up of independent actors collaborating voluntarily and without formal legal or organizational ties.

EMURGO is a for-profit company established to drive the commercial adoption of the Cardano blockchain. Its activities focus on business integration, investment, and development of solutions that expand the utility of Cardano. EMURGO is considered one of the pioneering entities, alongside the Cardano Foundation and Input Output Global (IOG, formerly IOHK), involved in the creation and early growth of the Cardano blockchain and its ecosystem.

A fixed period of time used in Cardano’s proof-of-stake system to organize block production and rewards. Each epoch lasts five days and marks the cycle for stake delegation, reward distribution, and protocol updates.

ESG stands for Environmental, Social, and Governance, a framework used to evaluate how organizations manage sustainability, ethical impact, and governance practices. In the blockchain context, ESG considerations often focus on energy efficiency, community inclusiveness, and transparent governance models.

The Extended Unspent Transaction Output (EUTXO) model is Cardano’s transaction accounting system, building on Bitcoin’s UTXO model. It extends UTXOs with the ability to carry data and scripts, enabling deterministic and secure execution of smart contracts while preserving transparency and parallelism in transaction processing.

Event streams are continuous flows of data that capture and broadcast activity from a system, such as transactions or state changes on a blockchain. They allow developers and applications to subscribe to updates as they happen, enabling features like live dashboards, alerts, or automated responses.

The FATF Travel Rule is a global anti-money laundering requirement issued by the Financial Action Task Force (FATF). It obliges virtual asset service providers (VASPs), such as exchanges and custodians, to collect and share identifying information about the sender and recipient when transferring digital assets above certain thresholds. The Travel Rule, however, is not digital asset specific but applies to all financial intermediaries, originating from traditional wire-transfer regulations.

A faucet is a service that provides users with small amounts of tokens, typically for free, to test or experiment with a blockchain network. On Cardano, faucets are mainly used to distribute test ada (tADA) on testnets, allowing developers and users to try out transactions, smart contracts, or applications without using real ada.

A small amount of tokens paid to process a transaction on a blockchain. On Cardano, transaction fees are required to prevent spam, compensate block producers, and contribute to the treasury, with the exact amount determined by protocol parameters and transaction size.

A change in a blockchain’s protocol that results in a divergence from the existing rules. Forks can be soft, introducing backward-compatible updates, or hard, requiring all participants to upgrade to remain on the same chain.

A software that downloads and verifies the entire blockchain (i.e. the complete ledger, starting from the first block), ensuring all transactions and blocks follow the protocol’s rules. On Cardano, running an active full node contributes to decentralization and allows users to independently validate the ledger without relying on third parties.

A digital unit of value that is interchangeable with any other token of the same type and denomination. On Cardano, ada and other native tokens can be considered fungible when each unit of a token is functionally identical.

The very first block of a blockchain, serving as the starting point of the ledger. While not technically a block, the term is sometimes also used to refer to the initial configuration of a blockchain.

Genesis keys are special cryptographic keys created at the launch of Cardano and entrusted to the pioneering entities, Input Output Global (IOG, formerly IOHK), the Cardano Foundation, and EMURGO. They were used to manage the network in its early federated phase, before block production and governance were gradually decentralized and distributed to the community. With the transition to fully on-chain governance, introduced by the Conway era, the genesis keys are no longer functional within the protocol and effectively ceased to exist.

The third phase in Cardano’s development roadmap, focused on bringing smart contract functionality to the blockchain. Goguen was implemented through the Allegra, Mary, and Alonzo upgrades, which together enabled native tokens, multi-asset support, and the deployment of decentralized applications (dApps). During this era, Cardano also introduced Plutus, its purpose-built smart contract language.

In the context of blockchains, governance refers to the processes and rules by which decisions about protocol upgrades, parameter changes, and the allocation of shared resources are made. Cardano has transitioned to a fully on-chain governance system in the Conway era, defined by CIP-1694 and implemented through the Chang hard fork, where ada holders directly participate—individually or through delegated representatives—in shaping the network’s future.

A hard fork is a blockchain protocol upgrade that is not backward-compatible, requiring all participants to adopt the new rules to remain on the same chain. If consensus is not reached, a hard fork can lead to a permanent split into separate blockchains, as seen with Bitcoin and Bitcoin Cash.

The Hard Fork Combinator is Cardano’s unique mechanism that allows multiple protocol versions to be combined into a single blockchain. It enables seamless transitions between eras—such as from Byron to Shelley or Shelley to Allegra—without causing network fragmentation or interruptions.

A cryptographic algorithm that converts input data of any size into a fixed-size output data, called a hash. In blockchains, hash functions are used to secure data, link blocks together, and verify transactions, as even small changes in the input produce completely different outputs. Cardano primarily uses the state-of-the-art cryptographic hash functions Blake2b and SHA256.

The process of applying a cryptographic hash function to input data to generate a fixed-size output, known as a hash. In blockchains, hashing secures transactions and blocks, ensures data integrity, and makes it practically impossible to alter past records without detection.

The measure of computational power used in proof-of-work (PoW) blockchains, such as for instance Bitcoin, to solve cryptographic puzzles and secure the network.

A functional programming language known for its strong type system and emphasis on mathematical proximity / affinity . Cardano core protocol is largely implemented in Haskell to ease high assurance and reliability in blockchain applications.

Hierarchical deterministic (HD) wallets generate a structured tree of private and public keys from a single seed phrase. This allows users to manage multiple addresses securely and conveniently, as all keys and addresses can be restored from the original seed.

A wallet connected to the internet, making it convenient for frequent transactions but more exposed to security risks. Examples include mobile, desktop, or web-based wallets that store private keys online.

A hybrid blockchain combines elements of public, permissionless and private, permissioned blockchains, allowing some data or functions to be open and transparent while others are restricted to approved participants. This model is often used to balance transparency, efficiency, and privacy for enterprise or consortium use cases.

A Layer 2 scaling solution for Cardano designed to increase throughput and efficiency by processing transactions off-chain in so-called “heads.” These Hydra heads enable faster, low-cost transactions while still settling securely on the Cardano main chain, supporting applications such as micropayments and real-time interactions.

Hydra heads are off-chain mini-ledgers in Cardano’s Hydra Layer 2 protocol where participants can process transactions quickly and at low cost. They operate among a small group of parties, while the final state of the head can be securely settled back on the Cardano main chain.

In blockchains, an incentive is a reward or mechanism designed to motivate participants to act in ways that support the network’s security and operation. On Cardano, incentives are mainly provided through staking rewards, which encourage ada holders and stake pool operators to contribute to block production and decentralization.

Refers to a special phase in Cardano’s development launched in late 2019 to test staking and delegation before their rollout on mainnet. The ITN provided critical insights into stake pool performance, reward distribution, and community participation, directly informing the design and parameters of Cardano’s Shelley era

Cardano’s infrastructure refers to the core technical and organizational components that keep the blockchain running securely and reliably. It includes the Cardano node software, the layered protocol design (networking, consensus, settlement, and scripting), and the global network of stake pool operators that maintain decentralization and resilience.

A fundraising method in which new blockchain projects sell tokens to early backers, typically to raise capital for development. ICOs were especially common in the peak years of 2017–2018, when many projects used them to raise significant funds.

The Initial Tree Offering (ITO) was introduced on Cardano through the Cardano Forest initiative in collaboration with veritree. In this model, participants received fungible tokens representing individual trees they funded, which could then be exchanged for NFTs that served as permanent on-chain records of each specific tree donation.

A scalability feature in Cardano’s consensus protocol that allows transactions to be pre-validated before being added to blocks. By separating transaction validation from block production, input endorsers increase throughput and improve the overall efficiency of the network.

A standard developed within the Cosmos ecosystem that enables different blockchains to exchange data and tokens securely. It provides interoperability across independent networks by establishing trustless communication channels. As of mid-2024, Cardano has integrated IBC via a sidechain implementation, enabling interoperability with Cosmos SDK chains and Ethereum-compatible sidechains.

The Interledger Protocol is an open protocol designed to enable payments across different ledgers and networks, regardless of their underlying technology. It routes transactions through a chain of connectors, allowing value to move seamlessly between blockchains, banks, and payment systems without requiring direct integration. The ILP is planned to be integrated with Cardano.

Refers to the ability of different blockchain systems to communicate, exchange data, and transfer value seamlessly. In the Cardano ecosystem, interoperability is a key design goal, pursued through approaches such as sidechains, partner chains, and integration of cross-chain protocols like IBC and ILP.

The InterPlanetary File System (IPFS) is a decentralized, peer-to-peer protocol for storing and sharing files across a distributed network. Instead of using location-based addresses like URLs, IPFS identifies content by its cryptographic hash, making data retrieval more resilient and tamper-resistant. In the Cardano ecosystem, IPFS is often used to store off-chain data linked to tokens or NFTs, or for governance actions, with only the content hash recorded on-chain.

Input Output Global (IOG), originally founded as Input Output Hong Kong (IOHK), is a technology and engineering company responsible for the initial design and development of the Cardano blockchain. IOG is considered one of the pioneering entities, alongside the Cardano Foundation and EMURGO, that established and advanced the Cardano blockchain and its ecosystem.

An early implementation of the Cardano node, written in Rust, used during the Shelley testnets before the transition to the Haskell-based node. It served as a prototype for stake pool operation and delegation but was later retired in favor of the main Cardano node software.

Cryptographic keys used by Cardano stake pool operators to sign blocks. Unlike static keys, KES keys are designed to evolve over time, reducing the risk of long-term key compromise while ensuring secure and continuous block production.

Refers to the processes and tools used to generate, store, use, and protect cryptographic keys that control access to tokens and blockchain functions.

Refers to a private key and a corresponding public key generated through cryptography. In blockchains, the private key allows a user to authorize transactions, while the public key (or its derived address) can be safely shared to receive tokens.

Refers to the regulatory process by which financial institutions and service providers verify the identity of their clients. In the blockchain context, KYC is often required by exchanges, custodians, and other regulated intermediaries to comply with anti-money laundering (AML) obligations.

A protocol parameter that defines the target number of stake pools the network aims to support for optimal decentralization. It influences rewards distribution by making overly large pools less attractive, thereby encouraging delegation across a wider number of pools.

Represents the foundational infrastructure layer of blockchain. It encompasses hardware, protocols, and communication mechanisms, enabling interoperability and scalability across different networks.

Refers to the underlying blockchain protocol itself. Layer 1 encompasses the core functionalities and consensus mechanisms of a blockchain network, providing the foundation for decentralized transactions and data storage.

Built on Layer 1 blockchains to enhance scalability and functionality. Layer 2 includes technologies like sidechains and off-chain protocols, offering faster transaction processing, lower fees, and additional features.

A record-keeping system that tracks transactions and balances. In the context of blockchain, it refers to a decentralized digital ledger that stores a chronological record of all transactions.

Generally an older software or infrastructure platform that is still in use but may be outdated compared to modern technologies. In the blockchain context, legacy systems often refer to traditional financial or IT systems that new decentralized solutions aim to integrate with or replace.

A light node is a type of blockchain client that does not download the entire ledger but instead relies on full nodes for data verification. This makes it faster and less resource-intensive, allowing users to interact with the network—such as checking balances or sending transactions—without running a full node. In the Cardano ecosystem, wallets like Yoroi and Lace use light node approaches to provide accessible, user-friendly interaction with the blockchain.

Liquid democracy, also known as delegative democracy, is a hybrid governance model that combines aspects of direct democracy and representative democracy, allowing voters to choose between voting on issues directly or delegating their vote to a trusted individual or expert proxy. In Cardano’s governance system, this model is reflected in the ability of ada holders to participate directly or to delegate their votes to DReps (Delegated Representatives)

A process in proof-of-stake (PoS) blockchains that allows participants to stake their tokens to earn rewards while also receiving a derivative token that represents the staked assets, keeping them transferable and usable in other applications.

Refers to the total amount of ada currently delegated to a stake pool at a given time, determining its chance of being selected to produce blocks under Cardano’s Ouroboros consensus mechanisms.

A defined span of time during which tokens are restricted from being moved or sold, often linked to staking, vesting schedules, or incentive programs. Cardano’s staking system does not enforce a locking period, giving delegators the flexibility to move or spend their ada freely.

A lovelace is the smallest unit of ada, Cardano’s native token, with 1 ada equal to 1,000,000 lovelaces. The name honors Ada Lovelace, a 19th-century mathematician regarded as one of the first computer programmers.

The live, fully operational version of a blockchain where real transactions and tokens exist and have economic value. For Cardano, the mainnet launched in 2017 and serves as the production network, in contrast to testnets that are used for experimentation and development.

Mary was a protocol upgrade in Cardano’s Goguen era that introduced native tokens and multi-asset support to the blockchain. It enabled users to create and transact with custom tokens directly on Cardano without relying on smart contracts.

A specialized server in certain blockchain networks that performs functions beyond standard transaction validation, such as facilitating governance or providing additional services. Cardano does not use a master node architecture, as all block-producing nodes operate under the same proof-of-stake protocol rules through stake pools.

Represents a data structure used in blockchains for efficient data storage and verification. It combines a Patricia Trie (a space-optimized prefix tree) with a Merkle Tree (a hash-based data verification structure) for secure and tamper-proof data management.

A cryptographic data structure that organizes transactions into a tree of hashes, allowing efficient and secure verification of large data sets. By storing only the root hash, blockchains can prove that a transaction is included in a block without revealing or processing all underlying data.

Refers to additional information attached to transactions or blocks on a blockchain. Metadata can include details such as timestamps, transaction types, or user-defined data, providing context and enhancing functionality.

A sidechain protocol that connects Cardano to Ethereum Virtual Machine (EVM) environments. It enables smart contracts and dApps written for Ethereum to run on Cardano, expanding interoperability and developer access.

The process of validating transactions and producing blocks in proof-of-work (PoW) blockchains by solving computational puzzles. Miners compete to be the first to solve these puzzles and earn rewards.

Refers to the creation of new tokens recorded on a blockchain. The opposite of minting is burning, where tokens are removed from the circulation.

An Multi-Party Computation Wallet (MPC Wallet) splits private key control among multiple parties who jointly authorize transactions. Unlike traditional wallets, no single party ever holds the full private key, reducing the risk of theft or loss.

Measures decentralization by identifying the minimum number of entities that could collude to disrupt a blockchain. A higher coefficient indicates greater resilience against centralization.

Refers to tokens built directly into a blockchain’s ledger rather than relying on smart contracts for creation. Cardano supports native assets alongside ada, enabling users to create and transfer custom tokens natively.

A system of interconnected computers that exchange data and resources. A blockchain network specifically operates as a decentralized collection of nodes that maintain a shared ledger of transactions and operate through consensus mechanisms to ensure transparency, security, and trust. In Cardano, the network uses a peer-to-peer architecture run by stake pool operators and participants to validate transactions and produce blocks.

Generally refers to the technical base layer of a blockchain. It comprises the customized peer-to-peer system tailored for a distributed network, facilitating secure communication and interaction between nodes.

A computer or device running blockchain software that participates in maintaining a blockchain network by validating transactions, relaying data, or producing blocks. On Cardano, nodes can function as block producers, relays, or passive participants.

A unique digital token that represents a specific asset and is not interchangeable on a one-to-one basis with other tokens.

Refers to activities, data, or transactions that occur outside the blockchain network. Off-chain activities can include interactions through Layer 2 solutions, sidechains, or other means that do not directly involve on-chain operations on the underlying blockchain.

Refers to activities, data, or transactions that occur directly on the blockchain network. On-chain activities include transactions, smart contract executions, and any data stored on the blockchain ledger.

A system where blockchain participants make decisions directly on the ledger through voting mechanisms recorded and executed by the protocol itself. Proposals, votes, and outcomes are transparently tracked on-chain, ensuring that governance actions—such as protocol upgrades, funding allocations, or parameter changes—are verifiable and tamper-resistant.

Refers to software whose source code is publicly available for use, modification, and distribution. Cardano’s core infrastructure, including its node and smart contract tooling, is developed and available under open-source principles.

Refers to a feed that provides real-world data to on-chain smart contracts, bridging the isolated blockchain network and the external world. Because blockchains cannot directly access off-chain information, oracles fetch, verify, and relay data such as weather data, stock prices, or events, enabling smart contracts to execute based on real-world conditions.

Cardano’s proof-of-stake (PoS) consensus protocol, developed through peer-reviewed research. It secures the network by selecting slot leaders to produce blocks based on stake, with multiple versions such as Ouroboros Classic, Praos, and Genesis.

Refers to any participant node in a blockchain network that communicates and exchanges data with others.

The process by which nodes in a blockchain network find and connect to each other.

A Peer-to-Peer network is a decentralized communication structure where each node can act as both client and server, sharing data and responsibilities directly with others. In a blockchain context, this model allows nodes to broadcast transactions, validate blocks, and maintain a synchronized ledger without relying on central servers, making the system more robust and resistant to censorship.

Refers to the direct communication between participants in a network without the need for a central intermediary.

Performance in blockchains generally refers to throughput, latency, and efficiency in processing transactions.

A controlled blockchain network where participation requires authorization from a governing entity, such as a consortium or enterprise. These blockchains are often also private, meaning the ledger is accessible only to approved participants.

A blockchain that allows anyone to join, validate transactions, and participate in consensus without prior approval. The ‘permissionless’ describes the open and decentralised participation model. Such blockchains are typically also public, meaning the ledger can be read by anyone. Cardano is a public, permissionless network where participation is open to anyone.

A technique in blockchain design where block validation and propagation are optimized by overlapping processes. Cardano introduced pipelining to improve throughput and reduce block propagation delays.

Refers to the amount of ada a stake pool operator commits to their own pool. A higher pledge can marginally increase rewards and demonstrates the operator’s commitment to the pool’s reliability.

Cardano’s smart contract platform and programming language, based on Haskell. It enables developers to write secure, high-assurance applications that execute deterministically on the blockchain.

The unique identifier governing the minting and burning of tokens on Cardano. It defines the rules under which a token can be created or destroyed, ensuring consistency and control.

A privacy coin is a crypto asset designed to obscure transaction details, such as sender, recipient, and amount. Cardano is not a privacy coin, as transparency of transactions is a key feature of its design.

Refers to blockchain networks with restricted readability of the ledger, reserving access and control to a select group of entities. It prioritizes data privacy and confidentiality over increased decentralization.

A cryptographic key that allows a user to authorize transactions and control access to tokens.

The number of blocks a stake pool successfully creates within a given epoch. On Cardano, block production is determined by the Ouroboros protocol based on stake distribution and randomness.

In the context of Cardano stake pools, profit margin is the percentage of rewards retained by the operator after covering fixed costs. The remainder of rewards is distributed among delegators.

Refers to the ability of a blockchain to support complex scripts and smart contracts. Cardano achieves programmability through its Plutus platform and extended UTXO model.

Cardano’s community-driven innovation fund that enables ada holders to propose, discuss, and vote on projects to receive treasury funding.

A consensus mechanism where participants validate transactions and produce blocks based on the amount of stake they hold and commit to the network. Cardano uses the Ouroboros PoS protocol.

A consensus mechanism where miners compete to solve complex mathematical puzzles to validate transactions and create new blocks on the blockchain, requiring significant computational power.

In blockchain, protocol refers to the set of rules and standards that define how participants in the network interact, reach consensus, and maintain the ledger. It governs how data is structured, validated, and stored securely, as well as the processes for block production, rewards, and governance.

Refers to blockchain networks with open readability of the ledger, allowing anyone to access the data and providing full transparency on the ledger. Such blockchains are typically also permissionless, meaning that anyone can participate and validate transactions.

A cryptographic identifier derived from a private key that is used to receive transactions and verify digital signatures. In many blockchains, including Cardano, public keys are also used to generate wallet addresses and validate transactions.

A framework that manages digital certificates and key pairs to enable secure communication. In blockchain, PKI concepts support authentication and trust in cryptographic operations.

Refers to the minimum number of participants or stakes required to make a decision in a governance or consensus process. In Cardano’s governance, quorum requirements apply to voting on protocol changes and treasury use.

A Cardano-specific concept emphasizing decentralized finance (DeFi) applications connected to real-world economic activity. It highlights use cases such as lending, identity, and supply chain solutions.

Refers to physical or traditional financial assets, usually in the context of them being tokenized and represented on a blockchain.

A redeemer is data supplied to a Cardano smart contract when attempting to spend a transaction output. It works alongside datums and scripts to determine whether the spending conditions are satisfied.

Refers to the consistency and dependability of blockchain operations, such as transaction processing and block production.

A style of web interface that allows systems to communicate over HTTP in a standardized way. Cardano provides REST APIs through its node and related services to enable application integration.

The Reserve (or Cardano Reserve) is the portion of ada supply that was not distributed at launch and is held on-chain to support the network’s long-term sustainability. There is no central authority in control and it is gradually released through protocol rules, funding staking rewards and the Cardano Treasury, thereby linking network participation with future development.

Refers to the ada distributed to stake pool operators and delegators for participating in Cardano’s proof-of-stake system. Rewards come from transaction fees and the monetary reserve.

The address where staking rewards are automatically distributed to ada holders. Delegators can spend or re-delegate rewards without moving their principal stake.

An open standard developed by Coinbase to simplify blockchain integration. Cardano implements Rosetta APIs to make it easier for exchanges and custodians to support ada.

Refers to the point at which a Cardano stake pool has reached the optimal size for rewards distribution. Delegating to oversaturated pools reduces returns, encouraging stake to spread across pools.

Refers to the ability of a blockchain network to handle increasing transaction volumes without sacrificing speed, security, or decentralization.

Script context in Cardano is the information provided to a Plutus smart contract during execution, including details about the transaction. It ensures contracts evaluate conditions deterministically.

This refers to the component comprising the programming language, Plutus, where smart contracts sit and are executed.

Securitization is the process of converting an asset into a tradable financial instrument, often by pooling it in a dedicated legal entity and issuing debt claims or shares thereto.

Security in blockchains refers to the measures that protect the network from attacks, fraud, or unauthorized access. Blockchain security relies on cryptographic techniques, consensus mechanisms, and network architecture to ensure data integrity and resilience.

Refers to a type of token that represents ownership in a regulated financial instrument or asset, such as shares or bonds.

A seed, or seed phrase, is a sequence of words that encodes the information needed to recover a blockchain wallet. It serves as the master key from which all private keys and addresses are derived, meaning anyone with access to the seed can fully control a wallet’s tokens.

Refers to the component where the ledger function and its respective rules sit, allowing for the facilitation of transactions with ada. It employs EUTXO model, where transactions are represented as inputs and outputs.

A scalability technique where a blockchain is divided into smaller partitions (shards) that process transactions in parallel. Cardano does not use sharding, focusing instead on alternatives like Hydra and input endorsers.

The second era in Cardano's development focused on decentralization. Shelley introduced stake pools, delegation, and staking rewards, transitioning the network from federated to community block production.

A separate blockchain tethered to the main chain, enabling additional functionality or experimentation without affecting the primary network.

A penalty mechanism in some proof-of-stake blockchains where misbehaving validators lose part of their stake. Cardano does not use slashing.

A fixed time interval during which a block can be produced. Slots are grouped into epochs, and slot leaders are elected to create blocks during their assigned slots.

The stake pool chosen by the Ouroboros protocol to produce a block in a given slot. Their selection is based on stake distribution and verifiable randomness.

Self-executing code deployed on a blockchain that automatically carries out actions when the programmed conditions are met. On Cardano, smart contracts are written in Plutus and executed within the extended UTXO model.

A backward-compatible blockchain protocol change where upgraded nodes enforce new rules, but older nodes can still recognize blocks. Soft forks typically require a majority of nodes to upgrade to be effective.

A token designed to maintain a stable value by pegging it to an external reference such as a fiat currency or basket of assets.

Refers to the process by which ada holders assign their stake to a stake pool without transferring ownership of their tokens. This allows them to participate in securing the Cardano network and earn rewards, while the chosen pool operator uses the delegated stake to increase the pool’s chance of producing blocks.

A collective resource in a proof-of-stake (PoS) blockchain where the stakes of multiple participants are combined to increase the likelihood of producing new blocks and earning rewards. Pools are managed by operators who run the necessary infrastructure and distribute rewards proportionally to delegators, after deducting fees for operational costs.

The individual or organization responsible for managing a stake pool. SPOs ensure node uptime, performance, and reliability, and they share in the rewards generated by the pool alongside its delegators.

The process of participating in a proof-of-stake (PoS) blockchain’s consensus by committing tokens to help secure the network and validate transactions, usually in return for rewards. On Cardano, ada holders can either operate a stake pool or delegate their stake to an existing pool.

A Sybil attack is when a malicious actor creates many fake identities to gain disproportionate influence in a network. Cardano mitigates Sybil attacks through its staking model, where influence is tied to ada holdings.

A separate blockchain network used for experimentation and development without real economic value. Cardano provides testnets where developers use test ada (tADA) to trial dApps, transactions, and upgrades.

A unit or digital representation of value recorded on a blockchain.

The process of representing real-world or digital assets as tokens on a blockchain.

A defined set of rules for how tokens behave on a blockchain to ensure compatibility and interoperability.

A measure of the total value of tokens committed to a respective DeFi protocol.

A record of value or data transfer submitted to a blockchain and validated by the network. In Cardano, transactions follow the extended UTXO model and may include tokens, metadata, or smart contract interactions.

Transactions per second is a performance metric showing how many transactions a blockchain can process in one second.

The Treasury (or Cardano Treasury) is a decentralized funding mechanism built into the Cardano blockchain, with no central authority in control. Its purpose is to ensure long-term sustainability by financing the continuous development, research, and operation of the Cardano blockchain and its ecosystem. Utilization of treasury funds is decided collectively by ada holders through on-chain governance. To date, the most notable initiative supported by treasury funds is Project Catalyst.

Refers to a period during which tokens that have been delegated or staked cannot be immediately withdrawn or transferred. While many proof-of-stake (PoS) networks impose an unbonding period, Cardano allows ada to be delegated without lock-up, meaning tokens remain liquid and transferable at all times.

A type of token that provides access to specific functions, products, or services within a blockchain network.

A model of tracking balances where tokens are represented as outputs of previous transactions that can be spent in new transactions. Cardano extends this model through its EUTXO design.

A participant that verifies transactions and produces blocks in a proof-of-stake system. In Cardano, validators are realized as stake pools elected through the Ouroboros consensus protocol.

A major Cardano upgrade in 2022 that improved scalability, Plutus smart contracts, and transaction efficiency. It introduced features like reference inputs and inline datums.

A cryptographic tool that produces a random output along with a proof that the result is correct. In Cardano, stake pool operators use VRFs to determine fairly and securely whether they are selected to produce the next block, ensuring unpredictability while allowing the outcome to be publicly verified

The fifth phase in Cardano’s original roadmap, focused on governance and self-sustainability. Its concepts are now realized in the Conway era through on-chain governance and treasury mechanisms.

A software application or device that stores and handles public and private keys, enabling users to interact with a blockchain by sending, receiving, and managing their tokens and transactions.

A unique alphanumeric identifier derived from a public key that designates the destination for tokens on a blockchain. It enables participants to send and receive tokens securely while preserving pseudonymity. On Cardano, wallet addresses can also include staking credentials, linking them to delegation and rewards.

A blockchain and interoperability protocol that enables non-custodial, bidirectional cross-chain transactions with multiple networks, including Cardano.

A wallet that is connected to the internet but with enhanced security features compared to hot wallets, often used for custodial or enterprise solutions. It balances accessibility with protection.

Web2 refers to the current era of the internet characterized by interactive platforms, user-generated content, social networking, and centralized services controlled by major companies.

Refers to the concept of a decentralized internet powered by blockchain, where users have greater control over data, identity, and digital interactions.

A light wallet for Cardano developed by EMURGO, providing quick and easy access to ada without downloading the full blockchain.

Cryptographic techniques that allow one party to prove knowledge of information without revealing the information itself.

A Layer 2 scaling solution that batches many transactions off-chain and submits a validity proof on-chain. Though not natively implemented in Cardano, zkRollups are studied as part of its scalability research.