Amortization
Amortization is the total number of years your mortgage would take to pay off in full at the current payment. In Canada it is usually 25 or 30 years. It is different from your term — the length of time your current rate and contract are locked in.
Amortization sets your payment size. A 25-year amortization on a $500,000 mortgage at 5% costs about $2,908/month; the same loan at 30 years costs about $2,668/month — roughly $240/month lower, but you pay tens of thousands more in interest over the life of the loan.
At renewal, you can usually keep the same remaining amortization or shorten it. Extending amortization beyond what's left generally requires a refinance, not a straight renewal, and may trigger the OSFI stress test if you're staying with an insured mortgage.