I haven't looked them up, but I can hazzard a guess that they are all the same thing. Celegorm is right in explaining what they do.
Windows backup is a decent enough peice of software, providing if disaster strikes that you use a HDD of equal size or larger (I've ran into problems with trying to recover an image onto a smaller disk - even when the used space would comfortably have fitted within it).
Norton Ghost (As in, the good old ghost - not the crap they call Norton Ghost now) was brilliant at imaging volumes.
It really boils down to what type of backup are you looking for? A disk image backup will backup the entire disk/volume into a file or regular backups will backup individual files to a location you choose.
Have a look at Paragon Backup - they do a free version that I've used years ago. It was half decent then, and it's free.
Backup & Recovery Free Edition - Overview
It's based on their comercial version. The only reason I know about this is a few years ago I had to use a realignment tool for shifting data from a HDD to a SSD and it was provided by paragon. Worth a look.