What is referred to as debt securities with maturities of less than one year?

Debt securities with maturities of less than one year are referred to as "bills." This classification typically includes instruments like Treasury bills (T-bills) in the context of government debt, which are sold at a discount and mature at par value, allowing investors to earn interest without periodic coupon payments. Bills are characterized by their short duration, making them less sensitive to interest rate changes compared to longer-term debt securities, which can lead to higher volatility and risk.

On the other hand, bonds generally have longer maturities and typically provide periodic interest payments, while notes are commonly associated with obligations that usually have maturities ranging from one to ten years. Gilts specifically refer to government securities issued in certain countries, often in the context of UK government debt, and can include a broader maturity spectrum, not limited to short-term instruments. Therefore, the term "bills" correctly identifies debt securities that fit the specified criterion of having maturities shorter than one year.