Once upon a time there was a user that wanted to install firefox.
The user tried to do pacman -S firefox but it didn't work. The all
mighty pacman reported that firefox-3.2.4-1.i686.pkg.tar.gz could not
be found on his mirror. So the user tried pacman -Sy firefox. It
worked and the user rejoiced since he could once again go and troll /h/.
But all was not good. The user had made a grave error!
See, when the user told the almighty pacman to -Sy firefox, pacman did