A heads-up display, or HUD, was a view screen projection that functioned as a form of visual aid. HUD units were fitted into the helmets of Imperial cadets who were training at the Arkanis Academy. They were capable of transmitting images. Zare Leonis wore one during a field exercise in Arkanis' wilderness.
The helmets of stormtroopers of the First Order were equipped with heads-up displays.
Mandalorian armor was also equipped with tactical heads-up displays in their helmets.