Here is my understanding :-

System image is exact replica of any given system. It contains OS + Disc data stored under drives + Installed softwares + Registry entries. So If i have taken
the image of say any run system\_A(say on windows as OS). Now I am given any other machine\_B without any software, I can make it up with image
of A.

Backup :- It just contains Disc data stored under drives. No OS, no installed files, no Registry entries.

Is this correct ? If yes , anyone can create the image of existing windows machine and install it on any machine without purchasing the windows license
for new machine. Is n't ? Probably when that user comes online, windows will check validity and invalidate it. Right ? But what if he does not come
online ?