Difference between df-h and fdisk command

df -h displays all of the mounted partitions. fdisk -l displays all of the partitions that exist on your disk.
Apparently there are some partitions which exist, but which are not mounted

fdisk shows you your attached disk spindles and how they are partitioned.
df on the other hand shows you the free space on filesystems. if you know a little bit of Linux or any variant of UNIX for that matter, you should know the difference between a filesystem and a disk device