Mortgage actually refers to the one-to-one loan that buyers need to repay to the bank on time after mortgage to buy a house. mortgage to buy a house refers to the loan behavior of taking real estate assets as collateral, obtaining bank loans and repaying the principal and interest in installments according to the contract, and the bank returns the collateral after the loan is paid off. Bank loans are divided into two repayment methods: equal principal and interest and average capital. Matching principal and interest means that the sum of principal and interest paid every month remains unchanged. The average capital is the total monthly repayment, in which the principal remains unchanged and the interest is calculated separately. There is also a saying that average capital's repayment method is more cost-effective than matching principal and interest. There are also misunderstandings in this formulation. After the loan is paid off, the lender needs to go to the bank where he works, and the bank will issue the corresponding loan repayment certificate, which is very important and is the necessary material for the Housing Authority to handle the mortgage cancellation procedures. A considerable number of people choose guarantee institutions to guarantee their mortgages when they are "business-to-business". After the mortgage is settled, they should also go through the formalities of canceling the guarantee in time and return the guarantee deposit.