Build a fixed-coupon bond and watch its cash flows discount into present values, a price, duration and convexity — then see how yield moves the price.
A bond's price is the present value of its coupons and principal, discounted at the yield. This bond pricing workbench lays out the cash-flow timeline, discounts each payment, and connects the price to duration and convexity on a draggable price–yield curve.
The cash flows are fixed, so a higher discount rate makes each of them worth less today. The longer the payments are in the future, the stronger the effect.
Duration is the slope of the price–yield curve: the approximate percentage price change for a small yield change. Convexity measures the curvature that the straight-line duration estimate misses.