>>31419022It can be used to store large amounts of pokemon (up to 3,000 IIRC), and transfer them forward to future generations. However, a pokemon that has been in one generation cannot go to a game before it. For example, if you catch a Pikachu in X, put it in Bank, put that Pikachu in Sun, and then put the Pikachu back in Bank, you will not be able to put it back in a generation 6 game, even if absolutely nothing about it was changed.
