Introduction to the File System Overview

The file system is an important part of any operating system. After all, it’s where users keep their stuff. In Mac OS X, the organization of the file system plays an important role in helping the user find files. The organization also makes it easier for applications and the system itself to find the resources they need to support the user.

The file system in Mac OS X has at its core a set of directories inherited from the Berkeley Software Distribution (BSD) operating system. While most of these directories are actually hidden by the Finder, many elements of the BSD world are still apparent. The file permissions model, symbolic links, and user home directories are all concepts inherited from BSD. Mac OS X also adds many of its own concepts to provide the user with a secure and elegant environment for managing files and folders.

The Mac OS X file system was designed to provide power and flexibility while maintaining the traditional ease-of-use users expect. To this end, the file system provides users with a consistent structure that makes it clear where resources are located. (This consistency also helps developers, whose applications need to know where important resources are located.) Other file system conventions, such as aliases, extension hiding, and display names also enhance the user experience.

Organization of This Document

The Mac OS X File System contains the following articles: