Important Files

/boot/grub             # Grub files
/etc/fstab             # Drive mounts
/etc/profile           # EnvVar for all users
/etc/group             # All groups available
/home/username/.bashrc # User-script @startup
/etc/init.d/           # Global start-scripts
/etc/ssh/sshd.config   # SSH config file
~.bashrc               # bash shell init scripts
~.zshrc                # zsh shell init scripts