May 03 2017
rm -rf [DirectoryName]
Use this in the parent directory when you are trying to delete a directory so you don't mess it up and nuke the wrong thing
sudo apt-get update
sudo apt-get upgrade
Update just updates your local list of what packages exist but doesn't actually install anything
Upgrade actually downloads and runs any updates that you found in the update command.
sudo apt-get autoremove
Removes any packages that are no longer needed, stuff that was installed because something needed it but that original thing has been updated and no longer needs it or it has been removed.