The core idea
Real yields measure the return available after accounting for inflation and therefore represent an inflation-adjusted cost of capital.
What is happening underneath
They matter for bond valuation, currencies, equities, gold and investment decisions because they influence the rate at which future real cash flows are discounted.
How investors should read it
A move in nominal yields driven entirely by inflation compensation is economically different from a move driven by real yields.
The same market move can carry different information depending on which maturity, issuer and risk premium is changing. Read the question together with the underlying concepts rather than treating one price move as a universal signal.