Why do games usually have loading screens? What is being loaded that requires a loading screen? A professional answer would be appreciated.
This isn't really a scripting question, but the reason for the loading screen is to load up voxels and parts of the place. It's loading everything for your client and for what you see on your screen. If you're referring to games that have created their own loading screens, then it's because they have a lot of assets. Scripting a loading screen will pre-load the assets at the same time hide the game behind a GUI.
Everything behind the GUI is loading. E.g. the players client/Computer parts and more loads hope that helps