--- title: "Glossary" --- Quick reference for terms used throughout the Pubky ecosystem. --- ## A **Aggregator** A service that collects and organizes data from multiple [Homeservers](https://pubky.org/explore/pubkycore/homeserver.md) to enable search, feeds, and discovery features. See [Aggregator](https://pubky.org/explore/pubky-apps/indexing-and-aggregation/aggregator.md). **Authentication** The process of proving ownership of a public key through cryptographic signatures, enabling secure access to Homeservers without passwords. See [details](https://pubky.org/explore/pubkycore/authentication.md). ## C **Capability Token** A cryptographically signed token that grants third-party applications limited access to a user's data on their Homeserver, similar to OAuth access tokens. **Censorship Resistance** The property of being difficult or impossible to block, censor, or control by any single authority. Pubky achieves this through decentralized [Mainline DHT](https://pubky.org/explore/technologies/mainline-dht.md) and distributed [Homeservers](https://pubky.org/explore/pubkycore/homeserver.md). **[Credible Exit](https://pubky.org/explore/concepts/credible-exit.md)** The ability to leave a service provider (Homeserver, app, etc.) without losing your data, identity, or social connections. A core principle of Pubky's architecture. ## D **[Distributed Hash Table (DHT)](https://pubky.org/explore/technologies/dht.md)** A decentralized key-value storage system distributed across many nodes. Pubky uses [Mainline DHT](https://pubky.org/explore/technologies/mainline-dht.md) for storing [PKARR](https://pubky.org/explore/pubkycore/pkarr/introduction.md) records. **[Domain Name System (DNS)](https://pubky.org/explore/technologies/dns.md)** Traditional system for translating domain names to IP addresses. [PKDNS](https://pubky.org/explore/technologies/pkdns.md) extends this to support public-key domains. **[DNS over HTTPS (DoH)](https://pubky.org/explore/technologies/doh.md)** Protocol for encrypting DNS queries using HTTPS, preventing surveillance and tampering. ## H **[Homeserver](https://pubky.org/explore/pubkycore/homeserver.md)** A web server that stores user data in a key-value format. Users can run their own or choose any provider. Data is stored per public key and accessed via HTTP/HTTPS. **[Homegate](https://pubky.org/explore/technologies/homegate.md)** A signup verification service for Homeservers, providing SMS and Lightning Network payment verification to prevent spam while preserving privacy. ## I **Indexer** See **Aggregator**. A service that crawls and indexes data from Homeservers to provide search and discovery features. ## J **[Jeb](https://pubky.org/explore/technologies/jeb-pubky-ai-bot.md)** AI-powered bot for the Pubky social network, providing post summaries and fact-checking capabilities using LLMs and web search. ## K **[Key Pair](https://pubky.org/explore/technologies/key-pair.md)** A pair of cryptographic keys (public and private) used for identity, authentication, and encryption. In Pubky, your public key IS your identity. ## M **[Mainline DHT](https://pubky.org/explore/technologies/mainline-dht.md)** The Distributed Hash Table used by BitTorrent, with 10+ million nodes globally. Pubky uses it to store [PKARR](https://pubky.org/explore/pubkycore/pkarr/introduction.md) records, providing censorship-resistant discovery. ## N **[Nexus](https://pubky.org/explore/pubky-apps/indexing-and-aggregation/pubky-nexus.md)** (Pubky Nexus) Production-grade indexing and aggregation service for [pubky.app](https://pubky.org/explore/pubky-apps/reference-app/pubky-app.md). Provides high-performance social graph API, search, and real-time notifications. **[Noise](https://pubky.org/explore/technologies/pubky-noise.md)** (Pubky Noise) Noise Protocol implementation for encrypted peer-to-peer communication in the Pubky ecosystem (work in progress). ## P **[Paykit](https://pubky.org/explore/technologies/paykit.md)** Payment protocol built on Pubky for payment discovery and coordination across Bitcoin, Lightning, and other methods (work in progress). **[PKARR](https://pubky.org/explore/pubkycore/pkarr/introduction.md)** (Public Key Addressable Resource Records) Self-issued, signed DNS-like records published to the Mainline DHT. Each record is tied to a public key and contains information like Homeserver locations. **[PKDNS](https://pubky.org/explore/technologies/pkdns.md)** DNS server that resolves public-key domains by fetching PKARR records from the Mainline DHT, bridging traditional DNS with decentralized identity. **Public Key** The public half of a cryptographic key pair. In Pubky, this serves as your permanent, self-sovereign identity (often called a "pubky"). **Pubky** 1. The decentralized web protocol and ecosystem, formally known as [Pubky Core](https://pubky.org/explore/pubkycore/introduction.md) 2. A user's public-key identity (e.g., "my pubky is z4e8s...") **Pubky app** Any application built on [Pubky Core](https://pubky.org/explore/pubkycore/introduction.md). A Pubky app uses the Pubky [SDK](https://pubky.org/explore/pubkycore/sdk.md) and [Homeservers](https://pubky.org/explore/pubkycore/homeserver.md) for authentication and data storage. See [Pubky Apps overview](https://pubky.org/explore/pubky-apps/introduction.md). **[pubky.app](https://pubky.org/explore/pubky-apps/reference-app/pubky-app.md)** The reference implementation of a Pubky app — a decentralized social media application built by Synonym, live at [pubky.app](https://pubky.app). It demonstrates how to build social applications on the Pubky protocol using [Nexus](https://pubky.org/explore/pubky-apps/indexing-and-aggregation/pubky-nexus.md) for indexing and the [pubky-app-specs](https://pubky.org/explore/pubky-apps/app-specs.md) data model. **[Pubky CLI](https://pubky.org/explore/technologies/pubky-cli.md)** Command-line tool for interacting with Pubky Homeservers, providing user operations, admin functions, and testing utilities. **[Pubky Core](https://pubky.org/explore/pubkycore/introduction.md)** The foundational protocol, Homeserver implementation, and SDK for building decentralized applications on Pubky. **[Pubky Docker](https://pubky.org/explore/technologies/pubky-docker.md)** Docker Compose orchestration for running the complete Pubky Social stack locally with one command. **[Pubky Explorer](https://pubky.org/explore/technologies/pubky-explorer.md)** Web-based file browser for exploring public data on Pubky Homeservers. Available at [explorer.pubky.app](https://explorer.pubky.app). **[Pubky Ring](https://pubky.org/explore/technologies/pubky-ring.md)** Mobile key manager app (iOS/Android) for securely managing pubkys, authorizing applications, and handling sessions. **[pubky-app-specs](https://pubky.org/explore/pubky-apps/app-specs.md)** Formal data model specifications for [pubky.app](https://pubky.org/explore/pubky-apps/reference-app/pubky-app.md), defining structures for users, posts, tags, and other social features. Any Pubky app that follows these specs can interoperate with pubky.app and its ecosystem. ## R **Recovery File** Encrypted backup of a user's private key and identity information, protected by a passphrase. Used for key recovery and migration between devices. ## S **[SDK](https://pubky.org/explore/pubkycore/sdk.md)** (Software Development Kit) Client libraries for building Pubky applications, available in Rust, JavaScript/WASM, and native mobile (iOS/Android). **Self-Sovereign Identity** Identity that is fully controlled by the individual, not dependent on any centralized authority or service provider. Pubky implements this via cryptographic key pairs. **[Semantic Social Graph](https://pubky.org/explore/concepts/semantic-social-graph.md)** A social network where relationships are tagged with meaningful metadata, enabling personalized content filtering, trust-based discovery, and user-controlled feeds. **Session** A time-limited authentication state that allows a client to access a Homeserver without repeatedly signing requests with the private key. ## T **Tag** User-defined label attached to posts, files, or other users to add semantic meaning and enable filtering/discovery in the [Semantic Social Graph](https://pubky.org/explore/concepts/semantic-social-graph.md). ## W **Web of Trust** Traditional model where trust propagates through social connections. Pubky extends this with the [Semantic Social Graph](https://pubky.org/explore/concepts/semantic-social-graph.md), adding semantic context to trust relationships. --- ## Quick Links - **[Main Documentation](/)**: Full knowledge base - **[Getting Started](https://pubky.org/getting-started.md)**: Get started with Pubky - **[FAQ](https://pubky.org/faq.md)**: Frequently asked questions - **[Comparisons](https://pubky.org/comparisons.md)**: How Pubky compares to alternatives - **[Vision](https://pubky.org/the-vision-of-pubky.md)**: Why we're building Pubky