Fixed vs Variable Mortgages
A fixed-rate mortgage keeps the same interest rate for an agreed period (often two, three or five years), so your payment is predictable while the fix lasts.
Variable and tracker mortgages can change when the lender's rate or the Bank of England base rate moves. They may start cheaper but carry payment uncertainty.
When the fixed period ends you usually move to the lender's standard variable rate unless you remortgage to a new deal.