Gunner was a generalized term for an individual who operated heavy weapons.
The position of gunner could be found on attack vehicles such as the Defoliator Deployment Tank or onboard medium or large spacecraft. During the Battle of Hoth, Rebel pilots like Wes Janson served as a gunners on T-47 airspeeders while Alliance gunners on the ground operated heavy weaponry.
Some infantry soldiers operating heavy guns were also referred to as gunners, such as the towering Gigoran mercenary Moroff, who wielded a Vulk TAU-6-23 "Blastmill" rotary blaster cannon.