---
title: Introduction to authentication modes
product: Unity Version Control
canonical: https://docs.unity.com/en-us/unity-version-control/uvcs-on-prem/authentication/authentication-modes
last_updated: 2026-11-03
generated_at: 2026-11-04T06:36:23.057Z
locale: en-us
---

# Introduction to authentication modes

> Compare the authentication modes that Unity Version Control On-Prem supports, and choose the mode that fits your environment.

Unity Version Control (UVCS) On-Prem supports several authentication modes. Each mode uses a different source for its list of users and a different way to identify users. Choose a mode based on the operating systems in your environment and the identity provider that your organization uses.

## How UVCS identifies users

A UVCS client sends security information to the server for validation. The basic token that the client sends is the security identifier (SEID). Each authentication mode builds the SEID in a different way and gets its list of users from a different source.

## Choose an authentication mode

The following table compares the available authentication modes:

|                       **Mode**                       |                   **User source**                  |         **SEID contents**         |                                 **When to use the mode**                                 |
| :--------------------------------------------------: | :------------------------------------------------: | :-------------------------------: | :--------------------------------------------------------------------------------------: |
|  [Local name](./local-user-auth.md#local-name-mode)  |          Local users on the server machine         |             User name             |             Your network is secure, and clients and server share user names.             |
| [Name and ID](./local-user-auth.md#name-and-id-mode) |          Local users on the server machine         |          User name and ID         |     All machines run the same operating system family, and share user names and IDs.     |
|                [LDAP](./ldap-auth.md)                |                     LDAP server                    |     ID from the LDAP mechanism    | Your organization uses an LDAP server, including in mixed Windows and Unix environments. |
|    [Active Directory](./active-directory-auth.md)    |            Active Directory main server            | Windows security identifier (SID) |         Your server runs on Windows and your organization uses Active Directory.         |
|     [User and password](./user-password-auth.md)     | `users.conf` and `groups.conf` files on the server |   User name and encoded password  |    You don't use LDAP or Active Directory, or your machines have no common user login.   |
|               [SAML](./saml/landing.md)              |                 Microsoft Entra ID                 |        Internal UVCS token        |               Your organization uses Microsoft Entra ID for single sign-on.              |

To change the mode that your server uses, refer to [Change authentication mode](./change-authentication-mode.md).

## Additional resources

* [Change authentication mode](./change-authentication-mode.md)
* [Server configuration files](../configure/server-configuration)
* [Client configuration](../client-configuration)
* [Security guide](../../security)
* [Manage On-Prem licenses](../on-prem-licenses)