What each of the three extensions actually holds

They are all ZIP-style files used by Minecraft Bedrock, but each has a different purpose:

  • .mcpack — a single pack. Usually it is one resource pack (changes appearance/textures/UI) or one behavior pack (changes game rules and entity behavior). When you open it, it installs into your resource/behavior pack list, ready to enable as needed.
  • .mcaddon — an add-on container. It can bundle several .mcpack files at once (commonly a matching resource pack plus behavior pack), so opening it once installs them all together and saves you from importing each one separately.
  • .mctemplate — a world template. After importing, it appears in the template list under “Create New World,” serving as a preset starting point for a new world.

How they differ from .mcworld

The key difference comes down to one sentence: none of the three above is the complete world you are actually playing. .mcworld is the complete save — inside it are level.dat and the db/ folder that stores chunks, blocks, and entities, and opening it turns it into a world you can keep playing (see What is .mcworld).

.mcpack / .mcaddon change the “gameplay and appearance,” .mctemplate provides a “starting point for creating a new world,” and .mcworld holds the “world itself.” Mixing up the extensions is often the root cause when the import location and what you expected don’t line up.

When you’re not sure which file you have

If the extension has been changed, the source is unclear, or it didn’t appear in the expected list after importing, don’t rush into repeated attempts. mcworld.app offers a free on-device diagnosis: it identifies whether it is a .mcpack, .mcaddon, .mctemplate, or .mcworld / Java world ZIP, and gives you a health report of the type, version, and structure to help you figure out where it should be installed. The diagnosis runs on-device by default and never overwrites your original file — every operation saves a new version, so the original is preserved and traceable.