The main difference between regular and unlimited cashback cards is the spending requirements and cashback cap.
You must typically meet a minimum spend requirement for a regular cashback credit card to unlock the maximum cashback rate. For example, you may be required to spend at least S$800 a month to earn 8% cashback on dining transactions. Failure to meet the minimum spend will result in a flat cashback rate (0.25%). Plus, there is usually a cashback cap in place. For example, a regular cashback credit card may have a monthly cap of S$100. This means the highest cashback amount you can earn is S$100, regardless of how much you spend.
As for an unlimited cashback credit card, you typically earn a flat cashback rate (from 1% to 1.7%) regardless of how much you spend. Although the cashback rate is much lower than a regular cashback credit card, there is no cashback cap. This means that is no limit to how much you can earn from your purchases, which is why an unlimited cashback credit card is perfect for big-ticket purchases.