When a lender makes a loan the value of the property is very important. If the borrower meets with misfortune and cannot repay, the loan may be foreclosed and the lender becomes the owner of the property.
Lenders then sell the property to recover their losses.
In other words, your home is used as collateral on the loan. Estimating the value of a home is the job of an appraiser. It is part of the underwriting process. You type in a street address and receive an estimate based on statistics. This information can also help you decide how much to offer a home seller.