What is bad about credit card gift cards?

I want to know what the bad about credit card gift cards, like visa and master cards. The one they sell in stores. Do you have to pat money to activate and then add money?

what is the major difference between a Master card and a Visa card?

can please someone help me, i have a presentation about plastic card, i got all the information needed but i still can’t figure out the difference between Master cards and Visa cards, aren’t they the same? i mean isn’t Visa card part of Master card, for it’s fully charged, just like the Master card, but [...]