--- title: Glossary --- # Waku Docs Glossary Definitions and usage of the terminology used in the Waku ecosystem. ### Bootstrapping Bootstrapping is the initial entry point of a [node](#node) to the [Waku Network](#waku). Once connected, other [peer discovery](#peer-discovery) methods can be employed to establish connections with fellow peers. ### [Content Topic](/overview/concepts/content-topics) A content topic is a string attached to [messages](#waku-message) to enable [protocol-level](#protocol) features like selective message processing and retrieval based on specific criteria. ### [Dappnode](https://dappnode.com/) Dappnode is an open-source platform that simplifies the hosting and management of decentralized applications and blockchain nodes, including [Waku](#waku). ### [Discv5](/overview/concepts/peer-discovery#discv5) Discv5 is a [peer discovery](#peer-discovery) mechanism using a Distributed Hash Table (DHT) to store [ENR](#enr) records, providing censorship resistance, load distribution, and enhanced network resilience. ### [DNS Discovery](/overview/concepts/peer-discovery#dns-discovery) DNS discovery is a [peer discovery](#peer-discovery) mechanism that allows the retrieval of an [ENR](#enr) tree from the TXT field of a domain name, enabling the storage of [node](#node) connection details and promoting decentralization. ### [ENR](https://rfc.vac.dev/spec/31/) Ethereum Node Record (ENR) is a specification used to represent and identify [nodes](#node), facilitating [discovery](#peer-discovery) and communication within the network. Besides connection details, `Waku ENR` also includes node configuration information like enabled protocol and shards. ### [Filter](/overview/concepts/protocols#filter) Filter is a [protocol](#protocol) that enables [light nodes](#light-node) to selectively subscribe to specific [messages](#waku-message) transmitted by [peers](#peer) using [content topics](#content-topic). It is designed to be a lightweight alternative for accessing the [Relay](#relay) network. ### [GossipSub](/overview/concepts/network-domains#gossip-domain) GossipSub is a [protocol](#protocol) for efficient and scalable information dissemination in decentralized networks commonly used in blockchain systems. ### Light Node A light node is a [resource-limited](#resource-limited) device or client that leverages service nodes to access the [Relay](#relay) network. ### [Light Push](/overview/concepts/protocols#light-push) Light push is a protocol enabling [light nodes](#light-node) to send [messages](#waku-message) to the [Relay](#relay) network and receive acknowledgments confirming that a [peer](#peer) has received them. ### Mostly Offline Mostly offline devices refer to clients who spend most of their time offline or disconnected from the internet and only occasionally to the internet and [Waku Network](#waku). Examples include browsers and mobile phones. ### Node A node is a device or client that implements Waku [protocols](#protocol) and leverages the [Waku Network](#waku) to enable secure and private peer-to-peer Web3 communication. ### Payload The payload field in a [Waku Message](#waku-message) contains the application data, serving as the business logic message transmitted between clients over Waku. Applications can encrypt the payload or employ encryption methods specified in [Waku Message Payload Encryption](#waku-message-payload-encryption). ### Peer A peer refers to other [nodes](#node) and participants of the [Waku Network](#waku) with whom communication and interaction are possible. ### [Peer Discovery](/overview/concepts/peer-discovery) Peer discovery is when a [node](#node) locates and gets information about other [peers](#peer) in the [Waku Network](#waku). ### [Peer Exchange](/overview/concepts/peer-discovery#peer-exchange) Peer exchange is a [peer discovery](#peer-discovery) mechanism that enables [light nodes](#light-node) to request and receive peers from other nodes in the network, allowing them to bootstrap and expand their connections without depending on [Discv5](#discv5). ### [Protocol](/overview/concepts/protocols) A protocol is a set of rules that enables [nodes](#node) within the [Waku Network](#waku) to perform various functionalities such as message sending, relaying, filtering, storing, retrieving, and more. ### Pub/Sub Publish/Subscribe (Pub/Sub) is an asynchronous messaging pattern where publishers send messages to topics, and subscribers receive messages from topics of interest, allowing efficient one-to-many communication. ### Pub/Sub Topic A Pub/Sub topic is a string that serves as an identifier for the topic of interest among [GossipSub](#gossipsub) peers. Peers interested in the same topic are likely to maintain a connection and forward messages received on that topic. ### [Rate Limit Nullifiers](https://rfc.vac.dev/spec/32/) Rate Limit Nullifiers (RLN) are a construct based on zero-knowledge proofs that enables rate limiting functionality while preserving the users's anonymity. ### [Relay](/overview/concepts/protocols#relay) Relay is a [protocol](#protocol) that extends the [GossipSub protocol](#gossipsub) to enable secure and censorship-resistant [message](#waku-message) dissemination among [peers](#peer) while preserving privacy. It also scales the [Waku Network](#waku) to accommodate many nodes efficiently. ### Resource-Limited Resource-limited refers to environments or devices restricting available resources, including bandwidth, CPU, memory, disk, and battery power. ### [RLN Relay](/overview/concepts/protocols#rln-relay) RLN Relay is an extension of the [Relay protocol](#relay) that uses [Rate Limit Nullifiers (RLN)](#rate-limit-nullifiers) to prevent spam economically by enforcing a rate limit on messages over time, imposing penalties, and facilitating network removal for spammers. ### [SDK](/guides/sdks-and-nodes) SDKs are tools, libraries, and resources to integrate Waku's private, secure, and censorship-free communication features into various applications. ### [Store](/overview/concepts/protocols#store) Store is a [protocol](#protocol) that enables the storage of relayed [messages](#waku-message) in the network, allowing offline peers to retrieve missed messages upon reconnecting to the network. ### [Transport](/overview/concepts/transports) A transport is a network mechanism that establishes connections between [peers](#peer) and enables efficient transmission, routing, and delivery of data packets. ### Waku Waku is a family of private, secure, decentralized, and peer-to-peer Web3 communication [protocols](#protocol) designed to operate in [resource-limited](#resource-limited) environments and suitable for [node](#node) or desktop application use. Additionally, these protocols collectively form the Waku Network. ### [Waku Message](/overview/concepts/protocols#waku-message) Waku Message defines the structure of messages in the [Waku Network](#waku), including the [content topic](#content-topic), [payload](#payload), and metadata for application-specific processing. ### [Waku Message Payload Encryption](https://rfc.vac.dev/spec/26/) Waku Message Payload Encryption provides guidelines for implementing secure and private communication in the [Waku Network](#waku). It covers encryption, decryption, and signing methods for message [payloads](#payload), focusing on confidentiality, authenticity, integrity, and unlinkability. ### [Waku Noise](https://rfc.vac.dev/spec/35/) Waku Noise is a specified way to use the [Noise Protocol Framework](http://noiseprotocol.org/) to build protocols that enable secure key-exchange mechanisms for encrypted communication with confidentiality, authenticity, integrity, strong forward secrecy, and identity-hiding properties.