Data version

A data version is a positive integer used in world save data to denote a specific version.

Usage
Upon loading a world, the game will check if the client has a data version newer than the selected world. If it does, the game will prompt the user to back up their world before playing.

Versioning
Every version of Java Edition since 15w32a, including minor releases and snapshots, has its own data version. Data versions may skip numbers between major releases, as the numbers in-between will belong to private development versions.