IO and Gemini. If you’re still a bit confused, that’s okay. Bitcoin Basics. Why do I have to buy bitcoins with credit card in order to buy other cryptocurrencies? The recipient will then be able to spend the gift card at one of a wide range of retailers. In what ways is it different from traditional currencies? Perhaps the simplest of all the wallets, these are pieces of paper on which the private and public keys of a bitcoin address are printed.