Help needed to understand better either back-up or clone !

Hi all…..Newbee here on How to safe guard by data & OS !

I’m having a hard time finding the difference & consequence in using these :
A - When is it better to clone a disc and when is it not recommended using it ?
B – When is it better to choose backing up “MY Computer” ?

I realize it is simple to ask but requires a complex answer. Anywhere I can read on this ?
I’m having great difficulty finding a clear understanding on my questions from Acronis manual or anywhere else!!
Thanks, Robert