With an annuity mortgage, you pay the same amount each month throughout the fixed interest rate period. This amount consists of both interest and repayment.
With a linear mortgage, you pay the exact same amount of repayment every month. As a result, the mortgage debt decreases in equal monthly portions. The interest also decreases monthly.
Interest only mortgage
An interest-only mortgage is a type of mortgage where you only pay interest on the principal and no repayment of the principal is made during the term of the loan.