Change a market par quote → see zero rates, forwards and discount factors react → understand why.
The yield curve shows interest rates across maturities. In this tool you shape a par yield curve with level, slope and curvature factors, bootstrap the zero-coupon spot curve from it, and derive the forward rates the curve implies between future dates.
Bootstrapping extracts zero-coupon (spot) rates one maturity at a time: each par bond's price pins down the next spot rate, given the spot rates already found for its earlier coupons.
Short rates are above long rates. The curve then implies falling forward rates, which markets often read as an expectation of lower future rates.