Definition: The term 'mortgage 0 interest' refers to a situation in which there is no interest on the principal amount owed on a mortgage loan, meaning that the borrower is not required or entitled to pay back the entire amount of their mortgage debt at any time. In other words, if you have borrowed money from a lender for an investment project, and the lender has agreed to only pay the principal amount of the loan back over a certain period of time (for example, 3 years), there would be no interest or penalties involved during that period. The borrower would not have to make any payments, so the risk for the lender would also be eliminated. In contrast, if you had borrowed money from a lender for an extended period (for example, 10 years) and were required to pay back the full amount of your mortgage debt at some point in the future, there might be interest or penalties involved. The borrower may have to make regular payments on their loan over time, or they could default on the loan if the lender decides not to honor their agreement. Overall, the 'mortgage 0 interest' scenario is an example of a situation where the borrower is in control of how much money they are spending on their mortgage debt and can decide when they need to make payments.