Linux organizes everything as files in a hierarchical tree structure. Understanding this structure is fundamental to system administration.
The Root Directory
Everything starts at / (root). Unlike Windows, Linux has a single unified file system.
Key Directories
/bin and /usr/bin
Essential user binaries and programs. /bin contains critical system binaries, while /usr/bin holds most user applications.
/etc
Configuration files for system-wide settings. This is where you'll find most configuration files.
/home
User home directories. Each user has a subdirectory here.
/var
Variable data files. Logs, caches, and temporary files that change during system operation.
/tmp
Temporary files. Usually cleared on reboot.
/opt
Optional software packages. Third-party applications often install here.
/usr/local
Locally installed software. This is where you'd install software manually.
Special Files
/dev- Device files representing hardware/proc- Virtual filesystem showing process information/sys- System information and configuration
Exploring the Structure
# See the structure
tree -L 2 /
# Check disk usage
df -h
# Find large files
du -sh /var/* | sort -h
Understanding the file system hierarchy helps you know where to find things and where to put new software.