Minecraft uses an older file format called Named Binary Tag to save world data. It was created by Markus Alexej "Notch" Persson, the inventor of Minecraft, to save tagged data organized in a tree.
All tags are of a certain type, have a name and mostly carry some data. The order of the tags plays no role, they are identified by their name.
There are some versions of the NBT format:
- Minecraft Indev used NBT with tags 0 to 10
- Version 19132: First known version number - used in Minecraft Beta 1.3
- Version 19133: Extension of the format by the integer array tag for the Anvil Format