Realspace

"Sir, the Electrum has reverted to realspace."

- A technician, to Wilhuff Tarkin

Realspace, also called normal space, or simply space, was the dimension in which all of the galaxy's residents lived. Because travel using sublight engines within realspace was slow, sentients found a technological way to access the shadow dimension known as hyperspace. A starship equipped with a hyperdrive would "jump" from realspace into hyperspace, and "revert" from hyperspace to realspace.

Species that could survive in the vacuum of space include exogorths and neebrays, as well as Cylo's cyborg Whale-ships. The purrgil were capable of flying through hyperspace.

Droids can also generally operate in space. R2-D2 and other Astromech droids did repairs outside the Naboo Cruiser that was used by Queen Amidala as she fled Naboo through the blockade of the Trade Federation, and the droids are shown exiting the ship with no preparations or extra gear. R2 would also sit exposed to space in various vehicles used by Anakin Skywalker and (later) Luke Skywalker.

At a point where K-2SO's human companions were grimly contemplating the possibility of dying in space, the droid unabashedly pointed out that he could survive in vacuum.