All about head-up displays (HUD)

What is a head-up display (HUD)? Where is it used ✓ What is the biggest HUD on the market? ✓ Innovations & trends ✓ Head-up displays for cars ✓ Airplanes ✓ Museums ✓ Trade fairs ✓ POS ✓ EVERYTHING summarized briefly and explained in detail.