Minecraft wiki entry for Creating_a_resource_pack, associated text: Next, inside your assets folder are your namespace folders. These help separate the files in your resource pack so that there is no confusion between which files are located where. If you plan on modifying or replacing vanilla resources, those files would go into the minecraft namespace folder. Custom additions should go in your own namespace folder, which for this tutorial will be named custom. In the future, you should use a significant or unique namespace so that there isn't a possibility of other resource packs confusing which files belong where when multiple packs are loaded.