whats the gs pokeball in pokemon?

Question

in pokemon they show the gs pokeball but they dont say what it does

Answer 1

In Japan, there was a promotion with Pokemon Crystal (involving cellphones, I think) where you could beam the GS Ball to your inventory with Mystery Gift. It could be taken to the Ilex Forest Shrine to battle a level 5 Celebi.
It's an open-ended thing for the anime GS Ball; it was only for that one filler bit. The GS Ball is unlikely to come up again.

Answer 2

it holds most secred stuff. I haven't watched pokemon for years...