A discount rate mortgage offers a percentage discount from the lender's standard variable rate for a set period of time.
When the standard variable rate fluctuates, the discount will remain fixed, however, the amount of discount and the period will vary from deal to deal.
Whilst it is likely that you will have to pay an early repayment charge for repaying a discounted rate mortgage early, these mortgages are more suitable for people who prioritise low initial payments at the expense of higher rates later on; for example first time buyers, where income is often initially stretched and there is a need to have some spare cash to spend on furnishing the new home.