What are Paper notes bought by an individual backed by a promise by the government to repay the money with interest after a certain period of time are called?

Paper notes bought by an individual that are backed by a promise from the government to repay the money with interest after a certain period of time are called government bonds or treasury bonds. These financial instruments are used by governments to raise funds and typically have a fixed interest rate and maturity date. Investors receive periodic interest payments and the principal amount upon maturity.