Mortgage is when a borrower promises to transfer a legal title or certain asset to a lender if the debt is not paid on schedule. It is a deal between a borrower and a lender in regards to an asset saying I will pay you on the day you schedule. Interest is revenue for the payee that is loaning the money which is an expense to the debtor. Revenue is earned money. An expense it money you owe someone. Interest is if I give you a 50 cent cake that is only worth 50 cent but I charge you 55 cent to make a profit. I made a 5 cent profit. The 5 cents was the interest I charge you which many times you will see in percentage form.
Reference: Charles T. Horngren. 2005. Accounting I &II. Pearson. Glossary
