What exactly does the Космос stone do?

The Космос Stone has the power to create interstellar bridges from one end of Космос to the other. It is, in effect, a portal to other parts of the universe making it an incredibly useful asset to the invading Thanos. The Космос Stone was used by Odin and Heimdall to build the Bifrost on Asgard, the радуга coloured bridge that allows Asgardians access to the nine realms. It is also a powerful Источник of energy, used to power Hydra’s weapons in Captain America: The First Avenger.