Ubuntu Filesystem Structure

Root Directory "/"

In Linux, "/" represents the root directory, and all directories are derived starting from the root directory.

Common Directories and Their Functions

/bin

• Stores binary executable files, which can be used even in single-user mode. They can be used by both the root user and ordinary accounts.

/boot

• Contains the Ubuntu kernel and boot files, such as vmlinuz-xxx and the GRUB boot loader.

/dev

• Stores device files, used for interaction between the system and devices.

/etc

• Contains system configuration files, such as user account and password files, service configuration files, etc.

/home

• The system's default user home directory. When a new user account is created, its home directory is created here by default.

/lib

• Stores library files, which are the dynamically linked shared libraries required when executable files run.

/media

• Provides mount points for removable storage devices, such as SD cards and USB drives.

/mnt

• Provides mount points for users to mount temporary filesystems.

/opt

• Stores optional application software packages, usually third-party applications.

/root

• The home directory of the root user, that is, the home directory of the system administrator.

/sbin

• Stores essential programs for system administration and maintenance, similar to /bin but mainly used during system startup and recovery.

/srv

• Service data directory, storing data related to services.

/sys

• A virtual filesystem that provides an interface between the kernel and user space.

/tmp

• Temporary file directory, used to store temporary files.

/var

• Stores frequently changing files, such as log files.

/usr

• UNIX software resources, not users' personal files, storing applications and files widely used by the system.

/proc

• A virtual filesystem that stores runtime system information and kernel information, directly stored in memory.

Absolute Paths and Relative Paths

Absolute Path

• A complete path starting from the root directory "/", for example /home/user/test/.

Relative Path

• A path relative to the current working directory. For example, ./test/ represents the test directory under the current directory, and ..\ represents the parent directory.