According to the repayment period, loans can be divided into three categories: demand loans, term loans and overdrafts. Demand loan means that the repayment period is uncertain at the time of loan, and the bank can issue a notice to recover the loan at any time; Term loan refers to a loan with a fixed repayment period, which is divided into short-term, medium-term and long-term loans according to the length of repayment period. Short-term loans refer to loans with a term of 1 year, medium-term loans refer to loans with a term of 1 year and less than 5 years, and long-term loans refer to loans with a term of more than 5 years. Overdraft refers to the amount that the current depositor overdraws from the bank according to the contract. This classification is conducive to monitoring the liquidity and capital turnover of loans, maintaining an appropriate proportion of long-term and short-term loans, and also helping banks to arrange the loan order according to the length of the repayment period of funds to ensure the safety of credit funds.