---
title: Introduction to the File System Overview
framework: macosx
role: article
path: apple-archive/documentation/MacOSX/Conceptual/BPFileSystem
---

# Introduction to the File System Overview

Conceptual information and guidelines describing the structure and usage of the Mac OS X file system.

## Organization of This Document

The Mac OS X File System contains the following articles:

- [File-System Domains](Articles/Domains.html#//apple_ref/doc/uid/20002281-CJBHIHFF) describes the high-level organization of the file system in Mac OS X. - [The Library Directory](Articles/LibraryDirectory.html#//apple_ref/doc/uid/20002282-BAJHCHJI) describes the standard subdirectories that are used to configure the system and user environments. - [The Developer Directory](Articles/DeveloperDirectory.html#//apple_ref/doc/uid/20002283-BCIJAGGG) describes the developer-specific directories that are installed with the Xcode Tools. - [Where to Put Application Files](Articles/WhereToPutFiles.html#//apple_ref/doc/uid/TP40001411-BAJHCHJI) provides guidelines on where applications should place non-essential configuration and support files. - [Files and the Finder](Articles/FilesAndFinder.html#//apple_ref/doc/uid/20002285-BCIJIGDE) describes the role of the Finder in managing the file system. It also explains some of the techniques the Finder uses to associate files with applications. - [Sorting Rules](Articles/SortingRules.html#//apple_ref/doc/uid/20002377-BCIJIGDE) explains the rules for ordering file and directory names in Finder windows. - [File System Guidelines](Articles/FileSystemGuidelines.html#//apple_ref/doc/uid/20002296-CJBHIHFF) offers tips and advice on how best to support Mac OS X file system features. - [Filename Extensions](Articles/FilenameExtensions.html#//apple_ref/doc/uid/20002297-CJBHIHFF) describes the Mac OS X support for filename extensions and how to support them in your applications. - [Display Names](Articles/DisplayNames.html#//apple_ref/doc/uid/20002298-CJBHIHFF) explains the difference between file names in the file system and the file names that users see. It also explains when your application should use display names. - [BSD Permissions and Ownership](Articles/BSDInfluences.html#//apple_ref/doc/uid/20002286-SW1) describes the principles behind file permissions and their implications for file management in Mac OS X. - [Access Control Lists](Articles/ACLs.html#//apple_ref/doc/uid/TP40002230-SW1) provides an overview of access control lists and how they are used to supplement BSD permissions. - [File System Comparisons](Articles/Comparisons.html#//apple_ref/doc/uid/20002287-BAJIGEDA) offers a comparison of features between HFS+ and UFS volume formats. - [Aliases and Symbolic Links](Articles/Aliases.html#//apple_ref/doc/uid/20002288-BAJBEHFB) describes the differences between aliases and symbolic links.

[Next](Articles/Domains.html)

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