A variable-rate mortgage is different to a fixed deal in that the interest rate is subject to change during the initial deal period. This means your monthly repayments could change making it harder to budget for them.
Variable deals often have lower interest rates than fixed deals initially. However, the rate could be increased so you need to make sure you budget for that.
The most common variable rate deals are tracker mortgages and discount mortgages.
Tracker rate - a tracker mortgage rate is pegged at a certain level above the Bank of England base rate, and rises and falls with it.
Discount rate - a discount mortgage rate is set at a certain amount below the lender's standard variable rate (SVR) and rises and falls with it.
Your lender's SVR is the rate you'll come onto once your introductory deal period is over. It's normally higher than both fixed-rate deals and other variable-rate deals on the market so it's normally worth remortgaging to save paying more each month.