Get disk usage information about the Desktop

$ du -h -d 0 Desktop
14G Desktop

Information about how much free space is available on computer

$ df -lh
Filesystem     Size   Used  Avail Capacity  Mounted on
/dev/disk0s2  111Gi  109Gi  2.3Gi    98%    /

You can read more about the flags with the man pages

$ man du
$ man df

This is my 100th post!!!