system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is happening when a game is loading?

If a game can render the scenery and objects as you're moving through the world, what's the point of waiting behind a loading screen?
gpt
So imagine a fast food place that can make burgers really fast, on demand. This is like the game when it's loaded and running, it's rendering stuff quickly and on demand. 

In the morning someone has to open the fast food restaurant, warm up the grills and get the ingredients out and prepped for rapid burger making. This is the loading screen, when the computers loads up all the information it will need to render at full speed and gets it ready. It does all of that upfront so it can just churn out burgers later without worrying.