The Blueprint Format
Bones / Groups
Bones are the building blocks of a model, they are used to build the structure of a model.
Bones are a default feature from Blockbench, learn more about them here.
Animated Java adds a few new features to bones, such as the ability to define custom NBT for the bone when it's summoned in-game.
Bone Config
The bone config can be accessed by right clicking the bone in the outliner and selecting Open Bone Config
.