Pokémon Bank is an add-on for the Nintendo 3DS system available in the Nintendo e-Shop. Using Bank as well as Poke Transporter, which comes with it, you can transfer Pokémon from 5th and 6th generation games to 7th generation games, as well as trading between different versions of the same generation. This is the software you'll also need to transfer Pokémon from the VC versions of Red, Blue, Yellow, Gold & Silver to any Gen 7 game. It's like the PC function in-game, only huge. There is an annual charge to use it, but it's not much - around $5 depending on where you live.