Technology Glossary




  • Cache

    Caching is the act of storing data or information for faster processing in the future. The cache will save pieces of information to preserve personal preferences or settings for future reference to increase the User Experience.

    Related Terms:
  • Call Duration

    The total time from when the call is successfully connected to when a participant ends it.

  • Cassandra

    Cassandra is a non-relational (NoSQL) database that can handle large data sets and access many simultaneous users. Cassandra handles data across multiple commodity servers to maintain quick responses and avoid failure points.

    Related Terms:
  • Channel Type

    The channel type defines the configurations and permissions (e.g., Livestream, Messaging, etc.).

  • Chat API

    Use a real-time chat and messaging API to outsource comprehensive chat features without managing data or storage internally.

  • CaaS is a software service that allows developers to integrate real-time chat and messaging into existing apps and websites.

  • Chat Channel (Chat Room)

    A Chat Channel uses asynchronous data transfers to send messages from each user to a specific channel. That channel can hold many users and display messages in real-time.

  • Chat Widget

    A chat widget is a ready-to-use, customizable chat window on a website. Chat widgets can host chatbot technology and enable users to converse with it.

    Related Terms:
  • Chatbot

    A chatbot is a software tool that developers can add to existing chat applications. Chatbots enhance the user experience by quickly answering questions or routing users to other professionals who can help provide customer support.

    Related Terms:
  • CSAM refers to any visual depiction, including images or videos, that depicts or represents a child engaging in sexually explicit conduct.

  • Client

    A client acts as the intermediary device between a user and a server. The client will send requests through a browser or application and display the response sent back by the server.

  • Cloud

    Cloud computing is the ability for many users to access server data remotely simultaneously. Users can send and receive requests via website or web application through the client-server relationship without physically interacting with the server.

  • Comet (Programming)

    Comet is a web application design paradigm that describes a continuous, two-way interaction between a server and a web browser using native HTTP methods.

  • Component

    A software component is a modular service that you can access independently through a larger application. Components can be organized throughout the file structure of an application or imported from a third-party provider.

  • Compose

    The Jetpack Compose Chat Messaging SDK is built on a low-level chat client and provides modular, customizable Compose UI components that you can easily drop into your app. You can also make API calls directly by using the client to add custom functionality.

  • Concurrent Connections

    Concurrent connections reflect the number of WebSocket connections on your chat app at the same time.

  • Conversational Channel

    A conversational channel is a place where users can converse. Examples include a website, real-time chat, Facebook Messenger, WhatsApp, Slack, Kik, etc.


  • Dashboard

    A dashboard houses primary app data, permissions options, billing info, and usage analytics data collected through your chat app. It also provides moderation controls.

  • Data portability refers to the capability and ease with which users can transfer and move their personal data and information between different applications or platforms.

  • Database

    A database is a storage center for information, traditionally defined as relational or non-relational (NoSQL). Databases read and write data from external sites or applications, providing users remote access over the internet.

  • Dedicated Stack

    A dedicated stack is an independent physical or cloud server that is devoted to a single tenant. Many healthcare and financial organizations use dedicated stacks to isolate sensitive data from unauthorized users for security purposes.

  • Dialogflow

    Dialogflow is an AI system designed to understand user inputs such as text or speech and provide relevant information in response. Dialogflow can respond to users with text or synthetic speech to enhance the user experience.



  • Fan-Out

    Fan-out is a messaging pattern where messages are broadcast in a one-to-many arrangement. A basic example of this pattern can be seen in the functionality of a Publish/Subscribe messaging system, as Pub/Sub implies the ability to route messages from a single sender to multiple receivers.


    FastAPI is an API framework written in Python for GET and POST requests. These requests follow OpenAPI convention and simplify the development process. JSON Web Tokens are pre-loaded in FastAPI and create unique user tokens based on UUID, email, and password.

  • Feed API

    Use Feed APIs to outsource comprehensive feed features without having to manage data or storage internally.

  • File Transfer Protocol (FTP)

    FTP is the standard protocol between client and server. The client will send a request to the server using a specified URL. Clients make requests via browser or application and can have methods such as GET or POST and information within the body. The URI path defines where the server is located and sends all data associated with the request. Once the server receives the request, it gets a response with a status code.

  • Filters

    Use filters when returning results with query endpoints. You can query using the custom fields you've defined on the object you are querying, as well as built-in fields.

    Related Terms:
  • Flag

    If a user sees or receives an inappropriate message, they can flag that message. The chat moderator is then notified of the content that has been flagged for their review and can make a judgment on what action to take next based on the contents of the chat.

  • Flutter

    The Flutter Chat Messaging SDK includes both a low-level SDK and reusable UI components bundled together in a simple sample app. Build a fully functioning Flutter mobile chat app with support for rich messages, reactions, threads, image uploads and videos.

  • Function as a Service (FaaS)

    Functions can be outsourced and added to production code by executing functionality at an edge server. Add FaaS as microservices or simple functions within microservices.

    Related Terms:


  • Gaming Interface

    A gaming interface allows users to interact with game functionality. Users can navigate through the game console and make selections or choices based on the options through the UI.

    Related Terms:
  • General Data Protection Regulation (GDPR)

    GDPR is a law maintained by the European Union to protect user-information stored electronically. The scope of GDPR extends to the transfer of data in or out of the EU as well.

  • Geocoding

    Geocoding (also known as forward geocoding to distinguish it from reverse geocoding) is the process of converting addresses (e.g. a house number, street name, zip code), into geographic coordinates (latitude and longitude).

    Related Terms:
  • Geolocation API

    A Geolocation API is a communication interface between a client device or application (client-side), and an application or service (server-side) that identifies and returns information about the client’s geographical location.

  • GET Request

    GET is a common method used in HTTP requests to retrieve data from a server.

  • Ghost retail is a new eCommerce term that refers to an on-demand marketplace or retail business with a brick-and-mortar location to fulfill online orders and deliveries but is not customer-facing.






  • Language Translation

    Chat messages can be translated on-demand or automatically, this allows users speaking different languages on the same channel. The source language is inferred from the user language or detected automatically by analyzing its text.

  • Latency

    Latency is the delay before a transfer of data begins following an instruction for its transfer.

  • Limit

    A limit is a parameter that sets a cap on the number of results that will return from an endpoint.

  • Live Streaming is the ability for users to observe different forms of media in real-time. As a source uploads content, users simultaneously receive packets of information without saving vast amounts of data. They can watch live videos or listen to music seamlessly without overloading local data storage.




  • Omnichannel communication refers to a multichannel approach to communication and sales that aims to provide customers with a seamless experience no matter if they shop in-store or online.

  • Open Graph (OG) Protocol

    Open Graph protocol facilitates developer simplicity by providing a universal protocol for cross-platform use. We can define the title, type, image, and URL with metadata, thus creating a graph object based on the information provided. Each entity within the page can function the same way, significantly minimizing repetition.

    Related Terms:
  • Options

    In addition to filtering and sorting, options are another tool to organize and filter data with query channels. Examples include watching the channel and limiting the number of channels or messages returned.

  • Owner

    Traditional default chat configuration provides elevated permissions to the owner of a channel, message, or user. For example, you can delete your message or update your name or profile.




  • Random Access Memory (RAM)

    RAM is live or “working” data and can be accessed immediately from any physical location within your computer. The information can be read or written in any order and “accessed randomly.”

    Related Terms:
  • React Native

    The React Native Chat SDK makes it easy to build in-app chat like iMessage, Telegram or Slack. Stream's React Native SDK is feature packed with rich messages (URL previews, user mentions, chat commands), reactions, threading, image & file uploading, and videos.

  • Reactive moderation responds to harmful content after users share it on a platform. This method typically relies on human moderators to monitor chat channels, and user reports to be actioned by moderators or administrators of the forum.

  • A real-time app is designed to function within a time frame that is effectively immediate for the user. The processing response happens so swiftly that any interaction seems to be occurring in real-time.

  • Real-Time Chat

    Real-time chat is a messaging service for applications that allow users to communicate in real-time.

  • Real-Time Computing

    Real-time data is information sent live from one source to another. An event will trigger a response and must guarantee that response within a specified timeframe, otherwise known as a “deadline.”

    Related Terms:
  • Real-Time Messaging Protocol

    RTMP or Real Time Messaging Protocol is a proprietary system that is utilized for streaming live video feeds to devices running Flash.

  • Real-Time Streaming Protocol (RTSP) is a network protocol that combines transcoding and programming to transfer video streams over the Internet.

  • Redis

    Redis is an in-memory database that parses Rapid Access Memory (RAM) for faster response times. By caching data in RAM, data is available instantaneously instead of disk storage, where information needs to be retrieved first.

    Related Terms:
  • Region

    You connect to Stream’s global edge network based on your local position at the time of the call.

  • Regional Setting

    The regional setting indicates the location of your chat app on the AWS infrastructure. Selecting the correct place for your app is critical; otherwise you might experience latency issues. You should also align your customer base with your regional setting.

    Related Terms:
  • A relational database stores object-based information and uses associations to pass data along.

    Related Terms:
  • Representational State Transfer (REST)

    REST is a formatting convention used for reading, writing, and updating objects. Developers that follow this convention refer to routes “RESTful.” Developers use this as a way to simplify readability when multiple individuals are writing to the same codebase.

  • Rich Text Format

    RTF is a document format that encodes formatted text and graphics for use in word processing documents and emails. It supports text formatting options like font styles, sizes, colors, and text alignment, as well as the insertion of images, tables, and other graphics. RTF files can be opened and edited in many word processing applications.

  • RocksDB

    RocksDB is a high-performance database using key-value pairs for faster data writing and storage. RocksDB focuses on applications that require low-latency access to data, such as real-time messaging queues or graph queries.

  • Role

    Roles determine the permissions of end-users and staff members at the application level. Examples of roles are Admin, Guest, User, Anonymous, etc.


  • Secure Reliable Transport Protocol (SRT) is a video streaming and technology stack designed to connect two devices and deliver low-latency video and other media across any network conditions.

  • Selective Forwarding Unit (SFU)

    A Selective Forwarding Unit (SFU) leverages transport protocol (UDP or TCP) and a server to route multimedia live streams to viewers in real time.

  • Sendbird offers a messaging platform.

  • Server

    A server is a physical or cloud storage system for functionality for other devices. The term comes from the idea that information is being “served” to its client. The server will receive some requests from the client and return a response.

    Related Terms:
  • Serverless Computing

    Outsourced computing services provide developers with production-ready tools to optimize applications. These services include Software as a Service (SaaS), Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Functions as a Service (FaaS). Cloud services can provide engineers with a fast, flexible alternative to in-house development.

  • SFU cascading refers to the process of connecting multiple Selective Forwarding Units (SFUs) in a hierarchical manner to handle video streams in a real-time communication system.

  • Shadowban

    Instead of a default ban, you can shadowban users from a channel, set of channels, or an entire app. When a user is shadowbanned, they will still be allowed to post messages, but any message sent during the shadowban will only be visible to the message's author and invisible to other users of the app.

  • SignalR

    Microsoft ASP.NET developed SignalR, a software library that utilizes traditional HTTP connections that allow real-time connectivity between server and clients.

  • Silent Message

    When you want to send a system, administrative, or transactional message, you may not always want to instantly alert the user or change the unread message count on a conversation. Silent Messages can be sent to a recipient without an “unread” notification appearing on their end.

  • Simulcast refers to the transmission of media through multiple concurrent signals to share content to more than one channel simultaneously.

  • Slash Commands

    Slash commands get their name due to the “slash” added before the command is used. Slash commands are associated with a web service and designed to make an HTTP request to the service provider.

    Related Terms:
  • Smart Notification

    Smart Notifications is a relatively new concept used to describe the various techniques designed to make real-time, push-style messaging (such as Push Notifications) more relevant, useful, and appropriate for individual users.

  • SMS (Short Message Service)

    SMS (Short Message Service) is a way to send short, 160-character text messages from one mobile device to another over the cellular telephone network.

  • Social Messaging

    Social messaging is an application or platform that allows users to chat independently or in groups. You can utilize social messaging as chat messaging or feeds delivered to clients in real-time.

  • Software as a Service (SaaS)

    SaaS is an outsourced option for developers who want to use services like our Chat API or Feeds but may not have the resources to build the functionality themselves. SaaS is offered on a term basis, and subscribers commonly have several plan options depending on what features they’re looking for. SaaS is a lightweight option as opposed to storing data on servers managed by the SaaS provider. SaaS can be an excellent solution for developers looking to provide their users a feature-rich experience without extending time to market.

  • Software Development Kit (SDK)

    SDKs are created for developers to quickly and easily integrate services into their existing applications. SDKs are custom-built and offered for specific platforms and frameworks. These kits can consist of infrastructure services as well as front-end kits for UI development.

  • Sort

    Sort is a parameter you can apply to queries. The sort function increases query options and flexibility. You can sort by field and direction or sort using multiple options. You can sort by parameters like last_updated or unread_count.

    Related Terms:
  • A STUN server (Session Traversal Utilities for NAT) is a type of server used in networking to help devices behind NAT (Network Address Translation) firewalls communicate more effectively with devices on the internet.

  • Subscribe Bitrate

    Bits received. A higher subscribe bitrate improves quality with more bandwidth, and a lower bitrate reduces bandwidth usage and buffering.

  • Support

    Support is typically a team of engineers focused on customer success and helping with any integration blockers or questions you may have.

    Related Terms:



  • URL Enrichment

    When enabled, messages containing URLs will be enriched automatically with image and text related to the message.

    Related Terms:
  • URL Unfurling

    URL unfurling is the complete breakdown of a URL into independent segments. You can repurpose these segments as Open Graph objects for simplified development techniques.

  • User

    Users are unique visitors to your chat app.

  • User Engagement

    User engagement is the measurement of how a user spends their time on a site. Improved user engagement will keep users engaged longer and increase time spent on the site or application.

  • User Experience (UX)

    User experience is determined by the design and logic of an app. User experience can be leveraged to drive conversions or point users towards a specific page.

  • User Generated Content (UGC)

    User-generated content (also known as UGC or consumer-generated content) is original, brand-specific content created by customers and published on social media or other channels. UGC comes in many forms, including images, videos, reviews, a testimonial, or even a podcast.

  • User Permissions

    The five default channel types (commerce, gaming, messaging, livestream, and team) come with different default permission policies preconfigured to best fit one use-case. For example, one of the default permission policies for the 'messaging' channel type "only allows users with a moderator or admin role to ban another user".

    Related Terms:
  • User Presence

    User presence allows you to show when a user was last active and if they are online right now. Whenever you read a user the data will look like this: The online field indicates if the user is online. The status field stores text indicating the current user status.

    Related Terms:


  • Video Freeze Rate

    The total length of a video pause. To calculate your video freeze rate: (The sum of video freezing duration per unit time / total audio duration per unit time) × 100%.

    Related Terms:




  • YAML

    YAML is a human-readable data serialization language that is commonly used to create configuration files for software applications. It is designed to be easy to read and write, and is often used as an alternative to XML and JSON. YAML files use a simple syntax that consists of key-value pairs, lists, and nested structures, making it easy to organize and manage complex data. YAML is widely used in the software development community for its simplicity and versatility, and is particularly popular for configuration management tools like Ansible, Docker, and Kubernetes.


  • Zombie Thread

    A zombie thread is a thread in a chat platform or application that remains active even after the user has closed or exited the application, often leading to performance issues or other problems.