A people of self-aware holograms living on the world Kasq in the 32nd century, descended from photonic servants of organic masters and represented at Starfleet Academy by the cadet SAM.
The Kasqians are introduced in Starfleet Academy. They began as holograms made to serve organic beings, and after their creators were gone they made a home on Kasq, where most no longer bother with humanoid form and exist as shifting photonic energy.
The cadet SAM, played by Kerrice Brooks, was built by the Kasqian Makers as an emissary to study organic life, with a view to deciding whether their people should rejoin it. Time runs far faster on Kasq than elsewhere, so years pass there during a few days outside.
The Life of the Stars, the eighth episode, reveals most of this when the damaged SAM is taken home for repair after the events of Come, Let's Away. The Doctor from Voyager, whom the Kasqians hold in high regard, remains with her there for years of local time.