This is the hierarchical list of folders and other items (called objectss) found in the left panel when you first open Grooper Design Studio. It is the basis for object navigation and creation in Grooper Design Studio.
Adding an object creates a new "node" in the Node Tree. It has a "tree structure" in that it "branches." Each new node added under another creates a new "branch". It is added one level down from the node it is created. What objects can be added under a branch are determined by the branch above it.