> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streampixel.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> Definitions for the terms used throughout the Streampixel docs.

Quick reference for terms you'll see in the docs and dashboard.

## Platform terms

<AccordionGroup>
  <Accordion title="Project">
    The basic unit on Streampixel. Owns a build, settings, share link, team access, and billing relationship. Most accounts have one project per Unreal application.
  </Accordion>

  <Accordion title="Build">
    A packaged Unreal Engine project (`.zip`) uploaded to a Streampixel project. A project can have many builds; one is "live" at a time.
  </Accordion>

  <Accordion title="Upload ID">
    The unique identifier of a build, returned by the [Upload File API](/resources/api-reference/upload-file-api). Use it to call [Distribute File](/resources/api-reference/distribute-file-api) and to correlate webhook events.
  </Accordion>

  <Accordion title="Region">
    One of three deployment regions: `us-east-1`, `europe`, `asia-pacific`. A project is bound to a region at creation. See [regions](/resources/concepts/regions).
  </Accordion>

  <Accordion title="Session">
    One viewer's connection to your stream. Has a lifecycle: requesting → queued → connecting → streaming → disconnected. See [session lifecycle](/resources/concepts/session-lifecycle).
  </Accordion>

  <Accordion title="Queue">
    When all your workers are busy, new viewers wait in a queue. The SDK exposes the viewer's queue position via the `queueHandler` callback.
  </Accordion>

  <Accordion title="API key">
    A per-user secret that authenticates REST API calls. Generate from the dashboard. Pair with your `userId` in every API request body. See [API keys](/resources/dashboard/api-keys).
  </Accordion>

  <Accordion title="Team member">
    A user invited to your Streampixel account with **Editor**, **Finance**, or **Viewer** access, scoped to specific projects. Members sign in with Google, Microsoft, or email/password. See [team members](/resources/dashboard/team-members).
  </Accordion>

  <Accordion title="Custom domain">
    A domain you own (e.g. `play.yourcompany.com`) configured to serve a Streampixel project. See [custom domains](/resources/dashboard/custom-domains).
  </Accordion>

  <Accordion title="Webhook">
    An HTTPS POST that Streampixel sends to a URL you configure when something happens to your build. See [webhooks](/resources/api-reference/webhooks) and the [event reference](/resources/api-reference/webhook-events).
  </Accordion>

  <Accordion title="Auto-release">
    The `autoRelease` flag on the upload API. When `true`, an approved build is automatically distributed. When `false`, you call [Distribute File](/resources/api-reference/distribute-file-api) yourself — useful for staged rollouts.
  </Accordion>
</AccordionGroup>

## Streaming terms

<AccordionGroup>
  <Accordion title="Pixel Streaming">
    Unreal Engine's technology for rendering frames on a server GPU and streaming them as video to a remote browser. Streampixel is built on top of Pixel Streaming.
  </Accordion>

  <Accordion title="Codec">
    The video compression format. Streampixel supports H264, VP8, VP9, and AV1. AV1 is highest quality but only works in Chrome desktop. See [codec settings](/resources/quick-start-guide/codec-settings).
  </Accordion>

  <Accordion title="Bitrate">
    How much data the stream uses, measured in kilobits or megabits per second. Higher bitrate = better visual quality, more bandwidth required.
  </Accordion>

  <Accordion title="Adaptive bitrate">
    A streaming mode that automatically adjusts bitrate to match the viewer's network. Set `resolutionMode: 'Adaptive Resolution Mode'` in SDK config.
  </Accordion>

  <Accordion title="QP (Quantization Parameter)">
    An encoder knob. Lower QP = higher quality + larger file size. Configure with `minQP` and `maxQP` in the SDK config. Defaults are sensible — only tune if you know what you're doing.
  </Accordion>

  <Accordion title="Latency">
    The time between input and visible result. Picking the closest [region](/resources/concepts/regions) is the biggest lever.
  </Accordion>

  <Accordion title="FPS">
    Frames per second. Streampixel reports both render FPS (in UE) and stream FPS (received by the browser). Aim for ≥ 30 FPS for usable interaction; ≥ 60 for smooth.
  </Accordion>

  <Accordion title="AFK timeout">
    A built-in inactivity timeout. After `afktimeout` seconds with no input, the viewer is warned, then disconnected. Configurable per project. See [AFK / idle timeout](/resources/web-sdk/features/afk-idle-timeout).
  </Accordion>

  <Accordion title="Disconnect code">
    A numeric code that explains why a session ended. See the full [disconnect codes reference](/resources/quick-start-guide/disconnect-codes).
  </Accordion>

  <Accordion title="SFU mode">
    A streaming mode where one Unreal instance feeds many viewers, used for one-to-many experiences. Set `sfuHost: true` for the host, `sfuPlayer: true` for viewers. See [multiplayer streaming](/resources/recipes/multiplayer-streaming).
  </Accordion>

  <Accordion title="WebXR">
    The browser standard for virtual and augmented reality. Streampixel supports WebXR via the `xrInput: true` SDK option. See [VR web integration](/resources/recipes/vr-web-integration).
  </Accordion>
</AccordionGroup>

## Acronyms at a glance

| Acronym   | Meaning                                |
| --------- | -------------------------------------- |
| API       | Application Programming Interface      |
| AV1       | AOMedia Video 1 (codec)                |
| FPS       | Frames per second                      |
| GPU       | Graphics Processing Unit               |
| H264      | A widely-supported video codec         |
| HMAC      | Hash-based Message Authentication Code |
| QP        | Quantization Parameter                 |
| SDK       | Software Development Kit               |
| SFU       | Selective Forwarding Unit              |
| UE        | Unreal Engine                          |
| VP8 / VP9 | Open video codecs from Google          |
| WebXR     | Web Extended Reality (VR/AR)           |

## Next steps

<CardGroup cols={2}>
  <Card title="Codec settings" icon="film" href="/resources/quick-start-guide/codec-settings">
    Pick the right codec for your audience and content.
  </Card>

  <Card title="Disconnect codes" icon="plug-circle-xmark" href="/resources/quick-start-guide/disconnect-codes">
    Every session-end code explained.
  </Card>
</CardGroup>