How Does Downloading and Updating Packages Work with Pacman?

[Kobold]

If you need info how you update the right way for this big update:

@Kobold

All what i did was (Timeshift snapshot, just in case):
1.Fresh start
2.Log out
3.crtl+alt+f3 to open TTY
4.sudo pacman-mirrors --fasttrack
5.sudo systemctl stop sddm
6.sudo pacman -Syu
and spammed Y to replace everything
7.reboot