systemd

package manager aliases

alias xi='sudo apt install'
alias xu='sudo apt update && sudo apt upgrade'
alias xs='apt search'
alias xr='sudo apt-mark auto'
alias xc='sudo apt autoremove'
alias xrm='sudo apt remove'
alias xinfo='apt info'
alias xlist='apt-mark showmanual'

major version upgrade

sudo apt update
sudo apt upgrade

sudo vim /etc/apt/sources.list
change old codename to new codename

sudo apt clean
sudo apt update

sudo apt full-upgrade
sudo apt autoremove

sudo shutdown -r now

download deb file

This is actually most useful on other distros when you need to get a particular deb file:

apt download $PKG