A fixed rate is there to protect you against future increases in interest rates. By locking in the rate, if the interest rate goes up, you are protected. However, if interest rates go down during the term you will have to wait till the end of the term until you can take advantage of the lowers rates. The reason for this is typically a lender will charge a penalty to break the mortgage during the term.

A fixed rate mortgage provides a set mortgage rate for a duration of time. Usually up to 10 years.
With these mortgages, your payment stays the same for this period of time. This can be very handy for people on a set budget.

Variable interest rates in comparison can have the payment or amortization change as interest rates change.
With these mortgages, you know exactly what your payment is month to month.
For this security, typically they come with higher interest rates than variable rate mortgages.

Learn more about Fixed Rate Mortages