---
title: Introduction to Multiple User Environments
framework: macosx
role: article
path: apple-archive/documentation/MacOSX/Conceptual/BPMultipleUsers
---

# Introduction to Multiple User Environments

Explains the system

## Organization of This Document

This programming topic contains the following articles:

- [Root and Login Sessions](Concepts/SystemContexts.html#//apple_ref/doc/uid/20002208-BCICFCJH) provides advanced material for daemon developers that describes the organization of the OS X process space and how that organization impacts applications. - [Supporting Fast User Switching](Concepts/FastUserSwitching.html#//apple_ref/doc/uid/20002209-BAJDIHBJ) provides general guidelines for application developers on how to make your application work in a fast user switching environment. - [User Switch Notifications](Concepts/UserSwitchNotifications.html#//apple_ref/doc/uid/20002210-CJBJDAGF) shows you how to handle the notifications that occur when the console user changes.

If you want to know more about the login/logout process, are writing a daemon or startup item, or want to know more about the daemons that run in the root session, see *[Daemons and Services Programming Guide](../BPSystemStartup/Chapters/Introduction.html#//apple_ref/doc/uid/10000172i)*.

[Next](Concepts/SystemContexts.html)

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