Concepts · Terminology
File formats and core concepts · 16 answers
- How Do Java and Bedrock World Formats Differ? Java Edition stores worlds as region/.mca (NBT); Bedrock uses db/ (LevelDB). The formats aren't interchangeable. mcworld.app diagnoses free on-device and offers one-way Java to…
- What Are Java's region/.mca Files? A plain-English look at region/r.x.z.mca files in Java Edition worlds: they store chunks by region in NBT binary, unlike Bedrock's db/ (LevelDB). mcworld.app diagnoses them…
- Behavior Packs vs Resource Packs: What's the Difference? Bedrock behavior packs (change game logic/entity behavior) vs resource packs (change looks/sounds), why they're stored apart from world files, and how mcworld.app handles Java…
- What Is a Minecraft Chunk? A chunk is a 16×16 world unit, and world data is stored and loaded per chunk. Learn what chunks are, how mcworld.app validates world structure on-device for free, and why…
- How Are the Overworld, Nether & End Stored in a World File? All three dimensions live in one save: Java uses folders like region/, Bedrock uses db/. mcworld.app diagnoses each dimension free, on-device, never overwriting your file.
- Where Are Game Mode, Difficulty & Game Rules Stored? Game mode, difficulty, and game rules are world-level settings stored in level.dat (NBT format). mcworld.app can read this metadata locally for free, with no upload by default.
- What is the difference between level.dat and level.dat_old? level.dat_old is the previous automatic backup of level.dat — a fallback clue when level.dat is corrupted, but not a full world backup. mcworld.app can diagnose level.dat…
- What Format Is NBT? Why Won't level.dat Open? NBT (Named Binary Tag) is Minecraft's binary tag format for world metadata, entities, and block entities; level.dat is NBT. mcworld.app reads these structures on-device, never…
- What Is a Minecraft Seed and What Does It Affect? A plain-English guide to Minecraft seeds: the random number that drives vanilla terrain generation, stored in level.dat. Plus why real-map worlds from mcworld.app are a different…
- World (.mcworld) vs Template (.mctemplate): What's the Difference? .mcworld is one specific world; .mctemplate is a template you use to create new worlds, spawning a separate copy each time. mcworld.app diagnoses and repairs these renamed ZIPs…
- What Is the level.dat File? And Why It Matters level.dat is the metadata file inside a Minecraft world save. It stores the name, game mode, seed, spawn point, and game rules. It must sit in the world's root folder; if it's…
- What are .mcpack / .mcaddon / .mctemplate files? .mcpack is a single resource/behavior pack, .mcaddon bundles multiple packs, and .mctemplate is a world template — none of them are a complete world, which is what sets them…
- What Is the db Folder (LevelDB) in Bedrock? The db folder in a Bedrock world is a LevelDB database that stores the actual world data—chunks, blocks, entities, and more. It plays a different role than level.dat, and if it…
- What is mcworld.app? mcworld.app is an independent iOS tool for .mcworld files, real-map Minecraft worlds, Java-to-Bedrock conversion, backups, and server hosting.
- Where Are Minecraft Saves? Understanding the World File Structure A Minecraft world save is made up of level.dat, db/ (LevelDB), levelname.txt, and more; the location differs by platform. On iOS it lives inside the app sandbox, so you must…
- What is a .mcworld file? How do you open it? .mcworld is a world import file for Minecraft Bedrock — essentially a ZIP archive with a changed extension. Open it on any device that has Bedrock installed to import the entire…
Other topics
Get it all done in one place at mcworld.app
Get the App Create, repair, convert, protect, and deploy your worlds—free diagnosis, and we never overwrite your originals.