The interest rate for a fixed rate mortgage is locked in for the full term of the mortgage. Payments are set in advance for the term, providing you with the security of knowing precisely how much your payments will be throughout the entire term. Fixed rate mortgages can be open (may be paid off at any time without breakage costs) or closed (breakage costs apply if paid off prior to maturity).
With a variable rate mortgage, mortgage payments are set for the term, even though interest rates may fluctuate during that time. If interest rates go down, more of the payment is applied to reduce the principal; if rates go up, more of the payment is applied to payment of interest. Variable rate mortgages may be open or closed.
A variable rate mortgage provides you with the flexibility to take advantage of falling interest rates and to convert to a fixed rate mortgage at any time.