The Linux filesystem follows a meticulously structured hierarchical architecture designed to optimize organization.
1. The Root Directory
The root directory (/) serves as the primary node from which all subordinate directories and files emanate.
2. System Directories
/bin– Nested immediately beneath/, this directory houses indispensable user-level binary executables required for fundamental system operations, including core utilities such asls, andcp./sbin– Residing within/, this enclave is dedicated to administrative binary executables, typically reserved for superuser privileges, encompassing tools likefdisk, andfsck./boot– Positioned within/, this directory encapsulates essential bootstrapping components, including kernel images, initial RAM disk images (initrdorinitramfs), and bootloader configurations (e.g., GRUB or LILO)./dev– An integral directory under/, it contains device nodes that interface with hardware and pseudo-devices, including block devices (/dev/sda), character devices (/dev/tty), and special-purpose system interfaces./etc– Situated under/, it serves as the nexus for system-wide configuration files, governing authentication, networking, service management, and daemon configurations./home– A subdirectory within/, it functions as the repository for individual user environments, encompassing personal data, user-specific configurations, and isolated workspaces./lib&/lib64– Encapsulated within/, these directories store dynamically linked libraries and kernel modules required for the execution of both user and system-level binaries./media– Nested within/, this directory serves as an ephemeral mount point for removable media such as USB drives and optical discs, automatically detected and mounted by the system./mnt– Situated under/, this directory provides a transient mount point for manually mounted filesystems and network shares./opt– A compartmentalized directory beneath/, allocated for supplementary, proprietary, or third-party software installations that do not conform to the native package management structure./proc– A pseudo-filesystem within/, dynamically populated at runtime to expose kernel and process information, offering real-time introspection into system operations./root– Nested directly under/, this directory constitutes the personal workspace of the root user, distinct from regular user directories housed within/home./run– Located within/, this volatile directory retains runtime data, including process identifiers (PIDs), sockets, and other ephemeral interprocess communication artifacts./srv– Embedded within/, this directory is conventionally designated for server-specific data such as web service roots (/srv/www) or FTP repositories./sys– A virtualized pseudo-filesystem under/, designed to expose kernel device parameters, power states, and system control interfaces, often interfaced viasysfs./tmp– Temporarily housed within/, this directory provides ephemeral storage for transient files, automatically purged upon reboot to maintain a clean state./usr– Subsumed under/, this directory serves as a repository for user-level applications, including system utilities (/usr/bin), libraries (/usr/lib), and documentation (/usr/share/man)./var– Situated beneath/, this directory accommodates dynamic, mutable data such as logs (/var/log), spool files (/var/spool), and temporary caches (/var/cache).