The StarCraft II Terran unit that transports ground units through the air is the Medivac.
The Medivac is a Terran support aircraft introduced in StarCraft II. Its primary transport role lets it carry infantry and other compatible ground units across terrain, including cliffs and obstacles. This makes it central to Terran drops, in which players unload troops behind enemy lines or into vulnerable mineral bases.
Medivacs also provide battlefield healing for biological Terran units. Their combination of transport and healing makes them especially useful alongside Marines and Marauders. A group of infantry supported by Medivacs can attack, withdraw, and recover health while remaining mobile.
The Medivac is often confused with the Viking because both are Terran flying units. Vikings are combat aircraft that can transform into ground-walking assault units, while Medivacs are support vessels without a comparable combat transformation. Ravens are spellcasters and detection units, not troop transports.