A head-up display (HUD) is any transparent display that presents data in the automobile without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view information with the head positioned "up" and looking forward, instead of angled down looking at lower instruments. The data shown on a HUD is usually kept to a minimum of the most essential information required while driving: current speed, navigation directions, the speed limit of the road, and so on.
HUDs can project the info onto a plastic panel that pops up in front of the driver just above the driver's display. The advantage here is that you don't have to look down to the driver's display while driving, thus the potential for distractions is limited.
Another type of HUD uses projection, which positions the data so that it appears to be projected outwards from the car, and not onto a plastic panel or the windshield itself. A projected HUD that appears near the nose of the vehicle, or slightly in front of it on the road, is said to result in the most rapid response times and best situational awareness for drivers.
Our spec pages mention whether a specific model has a HUD, and if so, which type it is. Projection HUDs are generally more expensive than the plastic panel pop-up types, and thus are usually to be found in more premium EVs.