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

# User identity

> Overview of how XBOX services identify players via XUID, and how GDK XUser and PlayFab identity link to sign-in, privileges, privacy, and user profile.

TBD: Provide an overview of how XBOX services identify players. Add information on how xuids work with GDK xuser and PlayFab identity.

## In this section

[User sign-in](/services/xbox-services/fundamentals/identity/auth/live-authentication-nav)
Provides an overview for account access, XAL, and XUser.

[User Profile](/services/xbox-services/fundamentals/identity/user-profile/live-user-profile-toc)
Describes the user profile, including reputation.

[Privileges](/services/xbox-services/fundamentals/identity/privileges/live-privileges-nav)
Provides an overview about which privileges an XBOX services user has and how that affects your title.

[Privacy and permissions](/services/xbox-services/fundamentals/identity/privacy/live-privacy-permissions-nav)
Provides an overview of privacy and permissions on XBOX services.


## Related topics

- [Identity](/services/xbox-services/fundamentals/identity/index.md)
- [User identity and XUser](/build/core-features/common/user/player-identity-xuser.md)
- [User identity and XUser APIs in the GDK](/build/core-features/common/user/index.md)
- [Users](/build/core-features/common/user/user-toc.md)
- [Guest users overview](/build/core-features/common/user/users-guest-overview.md)