In video games there are different types of HUD.
-There is the Permanent HUD which mean that is always there. For example In the following games used in my moodboard like Battlefield 3 we can see that the mini map and the bullets reserve are permanent and the health percentages.
-There is the Pull up HUD which is determined by the player, it means that the suer can add on the HUD a specific HUD interface.
-Also there is the Action HUD which only appear in certain events during your game session. For example it can happen when you health is going really low and goes red, also when the bullets in your magazine is low.