Pok�mon Bank is a piece of downloadable software that allows for you to store various Pok�mon from your Pok�mon X & Y games on the internet. It requires a yearly fee of 500¥ and has storage for up to 3,000 Pok�mon. It also runs a trial for 30 days at any point until January 31st which is when it becomes a paid service.
Pok�mon Bank simply allows you to store up to 3,000 Pok�mon within 100 boxes on the Internet, away from the boxes you have in your game. With this, you also have the ability to transfer content between various Pok�mon X & Y games. It also has protections that prevent cheated Pok�mon from being able to be transferred to the Bank.
In addition to that, you have the ability to search through your boxes based on type, species and various other features.
Each download of Pok�mon Bank comes with the special app called Pok� Transporter which allows for the transfer of Pok�mon from Generation V games to Generation VI