A mortgage is a loan secured by property, such as a home. When you take out a mortgage, the lender registers a lien, also known as an interest in, or a charge on, your property. This means the lender has a legal right to take your property in some situations. They can take your property if you don’t respect the terms and conditions of your mortgage like paying on time and maintaining your home.
When you pay off your mortgage and meet the terms and conditions of your mortgage agreement, the lender doesn’t automatically give up the rights to your property. There are steps you need to take to remove those rights. This process is called discharging a mortgage.
In other words, Mortgage Discharge is a legal document which allows the removal of the mortgage registration on a property.
Source: Financial Consumer Agency of Canada