info about df -h

[gaspo <gaspolo@gmail.com>]

i have make this Command for upgrade my Debian...stable
apt-get update
"          upgrade .... after 5 minutS my debian finish the upgrade..
but when I make 
"df -h"
for see the free space on my Disk... i have how reply:
[00:17:51] [gaspo@sparc64:~] $ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda1              84T   63T   17T  79% /


BEFORE the upgrade....
i have 
[00:17:51] [gaspo@sparc64:~] $ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda1             4GB    2gb  EC.......
the size Was GigaBite
...
What is the difference?