When using a credit card, you generally incur interest charges on any balance not paid off by the payment due date. With a card with an intro APR period, you get a certain number of months at a reduced interest rate or with no interest. A card may offer an intro APR period on purchases, balance transfers, or both. Once the intro period ends, you’ll incur interest at the regular APR.
If you need to finance a big purchase, a credit card with an intro APR period on purchases can allow you to pay off the purchase over time without being charged interest. And if you need to move high-interest debt on one card to a balance transfer card with an intro APR period, that can give you some relief from interest charges and let you work on paying down just the principal of your debt instead of the principal plus interest.