an ghost image is an exact copy of the hd or partion on your hd. for example;

You get a new machine, you reinstall everything, then make a ghost image (Norton Ghost). You then have an exact image on what is located on your hd in 1 file. you put the file somewhere safe. The next day your ar missing some files, virus problems, word wont start or you have a bsof when windows starts up.

What you do then is look up the ghost image, start up ghost, select the file and click on yes and after 10 min (depens how big the ghost image file is ) you will have your system back when you just installed it.

Ghos images are used in enterprises where you have maybe 100 pc with all the same configuration, so you install 1 pc, make a ghost image and run the image over the remaining 99 pc and in a short time you will have working systems...

Simple... if you know how tough !