Let me explain with an example. Suppose you're studying in school or college, and suddenly there is a dangerous virus outbreak that forces the closure of schools and colleges for an extended period. The government or authorities decide that until schools reopen, studies will be conducted online. However, to participate in online studies, you need a mobile phone, but you don't have any money in your bank account to buy one. In such a situation, you ask your parents to transfer some money to you, but it takes 3-4 days for the funds to arrive. However, you urgently need a mobile phone, so in this case, you can use credit cards. You purchase a smartphone using your credit card and later make the payment for the amount you borrowed from the credit card company by the end of the month.