What exactly does the spazio stone do?

The spazio Stone has the power to create interstellar bridges from one end of spazio 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 spazio Stone was used da Odin and Heimdall to build the Bifrost on Asgard, the arcobaleno coloured bridge that allows Asgardians access to the nine realms. It is also a powerful fonte of energy, used to power Hydra’s weapons in Captain America: The First Avenger.