I would like to add to what @birger already said that currently Fedora
mounts /tmp as /tmpfs by default; that means that the /tmp directory
we access is in fact a sort of ram disk that is destroyed every time
we shut down our system.
You can learn more tmpfs here:
http://en.wikipedia.org/wiki/Tmpfs
https://fedoraproject.org/wiki/Features/tmp-on-tmpfs
https://ask.fedoraproject.org/en/question/25383/how-turn-off-tmpfs-on-fed...
(Don't know if this last link still applies though, need to check it)
-Martin