system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do video games save the position of many objects?

In a game like Fallout 4 or Skyrim, you can rearrange furniture, create stacks of objects, or set off a bomb that scatters debris everywhere. When you save and reload, everything is in the exact spot you left it. How does the game manage to save and keep track of everything's location in such a large landscape?
gpt
The game saves the coordinates and orientation of each item in a relatively small area (like a city in skyrim) and does this for all areas. Interiors like houses are separate areas.

 The state of the items are only loaded when you are in that area, it doesn't load the whole world at once. 

If you haven't visited an area before, the state won't be saved as nothing has changed.

It's worth noting the game saves the areas as you leave them in temporary saves that get written out to your game save when you actually perform a save.