---
title: Glossary
description: Key terms used throughout the c15t documentation.
---
### Core Terms

|Term|Definition|
|--|--|
|`subjectId`|Client-generated device/browser identifier (`sub_xxx`). Stored in the `c15t` cookie. Created on first consent save.|
|`externalId`|Your authenticated user's ID (from Clerk, Auth0, etc.), linked via `identifyUser()`. Connects a device to a user account.|
|`consents`|The **saved** consent state — `Record<string, boolean>` mapping categories to granted/denied. Used for gating scripts, iframes, and network requests.|
|`selectedConsents`|**Unsaved** toggle state — what the user has toggled in the dialog but hasn't submitted yet. Becomes `consents` after save.|
|`mode`|Client operating mode: `'hosted'` (full backend), `'offline'` (local only), or `'custom'` (bring your own handlers). Legacy alias: `'c15t'`. Set once in provider config. See [Client Modes](/docs/frameworks/react/concepts/client-modes).|
|`model`|Consent regulatory model derived from jurisdiction: `'opt-in'`, `'opt-out'`, `'iab'`, or `null`. See [Consent Models](/docs/frameworks/react/concepts/consent-models).|

### Regulatory Terms

|Term|Definition|
|--|--|
|`jurisdiction`|A privacy regulation code (e.g., `GDPR`, `CCPA`, `PIPEDA`, `QC_LAW25`) detected from the user's geolocation. Maps to a consent model. See [Consent Models](/docs/frameworks/react/concepts/consent-models) for the full mapping table.|
|GPC|Global Privacy Control — a browser signal (`Sec-GPC: 1`) indicating the user opts out of data sale/sharing. Honored when a policy sets `consent.gpc: true` (enabled by default in California presets).|
|TCF|IAB Transparency and Consent Framework (v2.3) — a standard for programmatic advertising consent in GDPR jurisdictions. See [IAB TCF](/docs/frameworks/react/iab/overview).|
|GVL|Global Vendor List — an IAB-maintained registry of ad-tech vendors and their declared purposes, used by the TCF consent flow.|