Based on the period involved in repayment of the debt obligations, the debt instruments could be classified into long-/medium-/short-term debt instruments.
Long-term Debt Instruments: Debt obligations for a period over three years are known as long-term debt instruments. They are Debentures/Bonds and Preference shares.
Medium-term Debt Instruments: Medium-term obligations range for a period between 1-3 years. The method of raising such funds will either be a debt issue or through the "Fixed Deposit" program of the companies.
Short-term Debt Instruments: Debt obligations for a short period payable within one year or less than one year are covered under money market instruments. They are Commercial Papers and Certificates of Deposits.