Eli5: How can games like minecraft or no mans sky be essentially infinite, yet take up a very small amount of storage?

Question

No mans sky is like 18GB or so on my PS4, yet there are 256 galaxies and literally around 18 quintillion planets. It can be played completely offline too, so it isnt coming from some server somewhere

I understand they’re procedurally generated, so they dont even exist until you pass through that area, but even after playing for countless hours and crossing thousands of miles of landmass, the save file is still extremely small

In: 1323

Answer 1

You know how in math class you can have a function like f=x^2 and you can draw a graph with a parabola in it? It’s the same idea here. There’s a function that, when given an input, will give you a fixed output. When x=2, f is always 4. It’s just that in the game it’s a lot more complicated. Ultimately there’s some sort of “function” that will always generate the same world in the same location.