Directory

Purpose

/etc

System configuration files are stored here.

/bin

This directory holds binaries that must be accessible at all times and that ordinary users are likely to run.

/sbin

This directory is similar to /bin, but these binaries are likely to be used only by the system administrator.

/lib

Critical library files reside here.

/boot

This directory holds system boot files. These files may include the kernel, the boot loader, and similar files.

/usr

This directory tree holds extended system files, including its own /usr/bin, /usr/sbin, and /usr/lib directories. These files aren't necessary for basic system operation, but they may include program files for word processors, Web browsers, graphics programs, server programs, and other tools important to users.

/usr/local

This directory tree holds locally compiled programs in a directory that can be protected from package-management tools or system reinstallation.

/opt

Third-party commercial applications typically reside in this directory.

/var

System files of a transient or variable nature reside here, such as log files, mail queues, and databases.

/home or /users

Each user receives a separate subdirectory of this directory as a home directory.

/root

This directory is the root user's home directory.

/tmp

This directory is temporary "scratch space" for all users.

/mnt or /media

These directories or their subdirectories hold removable media, such as DVD-ROMs or flash disks, although some systems place removable media elsewhere.

/dev

UNIX device files reside in this directory, enabling programs to access hardware devices.