I am sure that most of you know what an Amazon Gift Card is. Well, I don't. I didn't get into Amazon until just recently. So what is an Amazon Gift Card? Is it a code or a physical good? If I want to (this is an example) give away some Amazon Gift Card do I have to deal with all the trouble of sending it to them in a letter or can I just PM it to him/her with the code that they put into their Amazon account and they'll balance will increase or something. Please someone explain.