HUD stands for heads-up display. This technology essentially shows information on the windscreen of any vehicle (be it a plane, a car, or anything else).
This information can span from speed to GPS directions.
The main practicality of heads-up displays is their ease of use and the fact that they allow drivers or pilots to not take their eyes of the road.
Like most technologies that have been commercialised over the last few years, heads-up displays were originally developed by the military.
Heads-up displays rely on a series of different factors to actually work to the end they were created for.
Some of these factors include field of view, collimation, eyebox, (an optical collimator), luminance and contrast, boresight, scaling and compatibility.
Often, heads-up displays are confused with augmented reality, however, they are not AR products as of today.
In fact, today’s HUD displays only display information about the vehicle, in the future it might be possible that vehicles screens will act like giant AR glasses.