Real yield is the number that actually tells you whether you are getting richer. A 6% nominal yield with 7% inflation is a losing trade; a 2% nominal yield with 0% inflation is a decent one.
Rising real yields are a headwind for gold, long-duration growth stocks and anything valued off distant cash flows, because the discount rate on those cash flows has genuinely gone up rather than just tracking inflation.
Example: the 10-year nominal yield is 4.30% and the 10-year breakeven-inflation is 2.35%. The real yield is 1.95%. If nominal yields rise to 4.60% while breakevens stay put, the real yield jumps to 2.25% and gc typically comes under pressure.
Related: nominal-yield, tips, breakeven-inflation, real-interest-rate, fisher-equation