what is the difference between normal Kernel 7.20 and the Kernel 7.20 EXT

what is the difference between the normal Kernel 7.20 and the Kernel 7.20 EXT

and please, do not post only a link to sap-note 1553300 or 1553301 ,

unfortunately, there's a lot of vaguely and unclear text in these sap notes, but

nothing that describes the difference between the "normal" and the "extended" kernel,

is EXT only another word for downward-compatible Kernel or is it more than this?

any helpful and understandable explanation of the difference? "normal" Kernel 7.20 and the Kernel 7.20 EXT