When you look at the root of the Linux filesystem, it may feel weird: folders with strange names. In fact, it’s pretty logical once you know the abbreviations and acronyms:
/bin USER PROGRAMS (binaries for users) /sbin SYSTEM PROGRAMS (binaries for root/admin) /etc CONFIGURATION FILES (configs and settings) /dev DEVICE FILES (device access files) /proc PROCESS INFORMATION (proc & kernel data) /var CHANGING DATA (logs, caches, queues, dbs) /tmp TEMPORARY FILES (temp stuff, wiped on reboot) /usr UNIX SYSTEM RESOURCES (apps, libs, docs) /home HOME DIRECTORIES (user homes, personal files) /boot BOOT FILES (kernel and bootloader) /lib SYSTEM LIBRARIES (libs and kernel modules) /opt ADDITIONAL APPS (third-party software) /mnt TEMPORARY MOUNT (manual mount points) /media REMOVABLE MEDIA (auto-mount usb/cd) /srv SERVICE DATA (web, ftp, db service data) /root ROOT USER HOME (root's home dir) /sys KERNEL INTERFACE (kernel & hardware info) /run RUNTIME DATA (runtime files, /var/run repl.) /lost+found RECOVERED FILES (fsck-recovered files)
This is the basic Linux skeleton. In almost every distribution, it looks the same.
The base of this cheatsheet has been circulating online, but it often had mistakes and lacked proper functional explanations. For example, it’s important to know that /usr does not contain your personal files (that’s what /home is for), but rather system resources: programs, libraries, and documentation available to all users. I also added root, sys, and run. Anyway, sharing it here 🙂