While is was installing something with the sudo apt-get install command I accidentally accepted the command
sudo apt-get install python3-
(yeah I know it is stupid to just accept this but I did a lot of those and i just continued to click y).
By executing the command I deleted my whole visual desktop of Ubuntu (I just had the plain shell but I recovered the visual desktop by now). I don't know if I am just stupid but nevertheless I want to create awareness that you shouldn't use the command.
If you can explain to me why happened what happened feel free to explain it to me.