Common Directories

Solid knowledge of directory structure on the operating system helps you quickly find files during file operations and system management.

The file system uses a hierarchical, tree-like directory structure. The base of the file system hierarchy begins at the root (often referred to as the forward slash / since the full path to it is /). Directories branch off the root. The tree root and branches are directories or folders, whereas leaves are files.

Here are the most common top level directories.

• /bin: command files executable by common users.
• /sbin: commands executable by non-common users. Sometimes, the directory may also hold commands executable by common users.
• /etc: system configuration files.
• /root: home directory for the system administrator (root or admin user).
• /usr: files and directories related to system users, as well as primary programs.
• /home: user home directory in which user files, including configuration files, documents, and data, are located.
• /dev: device files. In Linux, devices are represented by files so that they can be operated in the same way as files are operated.
• /media: file system mount points, which are typically used for installing removable media, partitions of other file systems (for example, DOS), network file systems, or any installable file systems.
• /lib: shared library files used by programs in /bin and /sbin directories.
• /boot: files used for booting the kernel and operating system.
• /var: variable files, including spool directories and files, logging data, lock files, and temporary files.
• /proc: a virtual file system capable of storing memory images of the operating system without occupying disk space.
• /initrd: directory where initrd.img files are mounted at the system boot time and the required device modules are loaded.
• /opt: optional files and programs. The /opt directory is often used by third-party developers to install or uninstall software packages.
• /tmp: temporary files required by users and programs. Files in the /tmp directory are automatically deleted.
• /lost+found: files recovered in system repair.