I want to apply for credit card. Can anyone tell me how does it work? Is it the same like debit card? Have to top up money inside then able to use?? Which bank offer lowest interest rate? What's the requirement?

You can take a look at this article: http://learn.moneysmart.sg/credit-cards/credit-card-basics/how-do-credit-cards-work/ It is different from debit card. In short, based on my own understanding, using a credit card is like using borrowed money. The bank extends a credit limit to you in which you can use the card to purchase item. At the end of a billing cycle, you care required to repay the amount that you have used. You can choose to repay only the minimum sum, but that would mean the bank will charge interest for the remaining amount that you have yet to pay back. Hence, it is easy to fall into debts if one does not pay the bills in full or promptly. This is another article that is informative: http://www.moneysense.gov.sg/Understanding-Financial-Products/Credit-and-Loans/Types-of-Loans/Credit-Cards/Things-to-Watch-out-for.aspx