What type of debt is characterized by a fixed repayment period and interest?

Long-term mortgages are a type of debt that is specifically designed with a fixed repayment period and interest. This means that borrowers agree to repay the borrowed amount over a set duration, typically spanning several years, with regular payments that include both principal and interest. This structured approach provides clear terms for both borrowers and lenders, allowing for predictable financial planning.

In contrast, the characteristics of other options do not align with this description. Short-term commercial bills are designed for shorter durations and often involve higher interest rates, which do not fit the idea of fixed repayment over a long term. Unsecured notes may also vary significantly in their terms and could lack fixed repayment schedules, making them less predictable. An overdraft is a more flexible borrowing arrangement, usually associated with a bank account, where the borrower can withdraw more money than is actually in the account, typically without a fixed repayment schedule. Hence, long-term mortgages stand out as the option that fits the criteria of having a fixed repayment period and defined interest.