some people who doesn’t know how the system of gift card works need to read this-once you buy a gift card, say this one, the gift card is sent in an email to the person you asked them to deliver.
it contains a code, which is different for every card, and is valid for one year from data of purchase(this one can be used to buy anything except Kindle eBooks & Apps).
the email is delivered instantly after completion of payment.
they can now buy anything from amazon, and during payment they can apply the code to reduce the price by that amount.
for eg,if you have to buy a product of rs 3000 and have a gift card of rs 2500, then after applying the code you will just have to pay the remaining balance, i.e, rs 500 through any other mode of payment of your choice(the amount of code will be deducted from the total cost of items in your cart).
similarly, if you buy an item worth rs 4000 and you have a gift card of rs 5000, then after applying the code, the total balance of you gift card remaining will be rs 1000, which can be used up in other purchases by appying the same code(amazon will have a record of the balance remaining on your gift card)