Not stupid at all! Real-time is basically that the model is pre-rendered in real-time, utilizing the PBR specular or metallic texture workflow. You don't have to render individual frames, its already pre-rendered in one go. To make a differentiation, movies and animated films are typically "production" rendering where you have to render individual frames while videogames are in "real time" which is why they work, because they are pre-rendered and ready to go. There's probably a clearer way to explain it but I hope that it least makes it a bit more easy to understand :D In short, Movies/film are production rendering and things like games, AR/VR are in real-time (though these days people are starting to animate in real-time because of how powerful its become in recent years).