Table of contents
<aside>
In all the examples provided, I use the Debian distribution in a VirtualBox environment
</aside>

bin: binaries (commands & programs) boot: boot-related configs dev: hardware devices (/dev/sdax) etc: system configuration files home: user directories lib: shared libraries & kernel modules lost+found: recovered files (fsck) media: media mount (CD, USB) mnt: temporary filesystem mounts opt: optional/third-party software packages
proc: virtual filesystem (process & kernel) root: root home directory run: runtime data (PIDs) sbin: system binaries srv: server data (FTP, Samba, web) sys: virtual filesystem (devices & kernel) tmp: temporary files (cleared on reboot) usr: apps, binaries, libraries and docs var: variable data (caches, database, logs)
Ctrl + A → go to beginning of line
Ctrl + E → go to end of line
Ctrl + U → delete to start of line
Ctrl + K → delete to end of line
Ctrl + W → delete word backward
Ctrl + R → search in commands history
Ctrl + L → clear terminal
man → manual
history → GNU history library
type → displays information about a command

alias → command shortcut

apt update → download package information from all configured sources
apt upgrade → install available upgrades of all packages currently installed
apt search → search for a specific package
apt remove → delete package, but keep configs
apt purge → fully delete package + configs
apt autoremove → remove unused dependencies
apt autoclean → clean old packages cache
inxi → system information tool for console and IRC