Interest rates are not a single number. Pick up a financial newspaper and you will see a whole list of them — one for each maturity and one for each type of borrower. Why does a 10‑year government bond pay a different rate than a 2‑year bond, and why does a highly‑rated company borrow more cheaply than a risky one? This chapter explains the two main patterns that shape those differences: the term structure and the risk structure.