Ghost32

Norton ghost is not a free program.
See http://en.wikipedia.org/wiki/Comparison_of_disk_cloning_software
Here you will find a program to make an image for free.

As to your question of what is the use of such program.
First of all to make a complete backup of a system. (it can also be used to clone a system to several other computers. (for windows use sysprep if you want to do this before making the image.))

So you mean if I want my windows vista clone on my another notebook. I need to first install windows vista than run ghost or first run ghost than install windows vista

'on my another notebook' you don't have to install anything if you are planning to put the image on that system. (hard disk will be overwritten with the image, so no point on installing anything on it.)

How can I make image

ghost mean that make and restore the image of HD on your machine as known cloning.  there is open source ghost image that you may want to try http://clonezilla.org/ 

i normally use norton ghost or clone image to make cloning on my HD on machine  

read this section of the link I provided. "Recovery Live CDs (Live USBs) that include disk-cloning utilities"
Here you find helper programs to make the image
You can not create an image of an active system partition. (so you will have to boot from anther media) The image file can also not be placed on the partition you image. (So a second disk will be needed in most case, and is prefered for speed)
So you boot your system for example with Ultimate Boot-CD, then you start you application to make images (for example Odin), you select the source (your vista installation hard disk, and as destionation you choose your second disk.)

I will not get back to you until tomorrow.

here a comparison chart on imaging software, and a nice discussion on it  :  http://disk-imaging-software-review.toptenreviews.com/

there are many free "imaging" softs :
http://www.runtime.org/driveimage-xml.htm

find more here :  http://www.thefreecountry.com/utilities/backupandimage.shtml

it's use; in short, is to take Everything on a partition or disk, and put that in a file, that can be restored on the same PC.
why on the same PC ?
every pc needs lots of drivers - different drivers for each motherboard .

if you want to restore to different hardware, you need more elaborated options to adjust the OS to different drivers, or do a repair install, to change the drivers.

nobus: why on the same PC ?

I don not agree complete with that. (same PC is not needed, same hardware is)
If you have a classroom with all equal computers (same hardware) You can install one with all needed programs and clone this to the other computers of the classroom. (use of sysprep is then needed)
Or for bussines, a departement working on same hardware, you can do the same.
Why you would do this? This saves time installing every pc seperate and in case one gets corrupt, you only have to restore the image instead of running through the install of OS and all the programs.

So for a home user, this usually is only used as backup software. Commercial this can be used as backup but also to clone computers.

it is only for him clarity's sake.

no bus is correct my friend, if the hardware is not the same you are going to get many pops up asking for hardware drivers if you use the image on a different PC example say you have a dell optiplex 760 and you want to ghost the image and use it on a optiplex 755, the hardware is different. then you have to consider if you windows keys will allow you to do this(corprate VLK is good for this). If you use at home try not to ghost more that 3 times on the same box.

Post taken Nobus an dboobyraw,
But see then note on Home user and commercial use.
If you are within commercial use I suppose you have a valid VLK Key. And I also noted quit well "Same Hardware" so optiplex 760 and 755 is not the same.
If you want to be more specific same motherboard with different speed of cpu can be working with cloning.