How many types of International calling card are using in USA, and what the procedure of using these cards?

it depends on where your planning to call to. your local pharmacy should have options for you and you get a card with a phone number to call. You call that number then you have to enter a pin number thats on that card and each card has like 5 dollars or 60 minutes on it, but that usually depends on the type of card. The pin number is used to know how much money or minutes you have left on the card.