Daniel plays Roblox and Minecraft almost every day. Mom asks if he actually knows what is happening inside the computer.

He doesn't. Neither do most people.

Both games look similar from the outside -- blocks, building, other players. But underneath they work in very different ways. And understanding the difference reveals something fascinating about how games and software work in general.

Start with what both games have in common. When you press a button or move your character, your device runs code constantly to calculate your position, what is around you, how objects should behave, and what to show on screen. All of that, every moment, to make the world feel real and responsive.

Now Minecraft.

A Minecraft world is enormous -- far larger than anyone could reasonably explore. And the entire thing doesn't exist in adv ...