I think delay discounting refers more generally to the process of weighting a reward now versus a reward later (https://en.wikipedia.org/wiki/Delay_discounting

I think delay discounting refers more generally to the process of weighting a reward now versus a reward later (https://en.wikipedia.org/wiki/Delay_discounting https://en.wikipedia.org/wiki/Delay_discounting), whereas delayed gratification refers specifically to opting for the latter.