When you see a credit card that offers 0% on purchases, it means that the interest rate for purchases made on the card is 0% for a limited period. So, essentially, you won’t be charged any interest for any purchases on the card, as long as you clear your card balance before the 0% rate ends and keep up with minimum repayments.
There may be some exceptions though, so it’s important to check the terms of your card. You should also bear in mind that many 0% credit cards will still charge for withdrawing cash.