SCNNode -- SceneKit

Overview

An SCNNode object by itself has no visible content when the scene containing it is rendered—it represents only a coordinate space transform (position, orientation, and scale) relative to its parent node.

To construct a scene, you use a hierarchy of nodes to create its structure, then add lights, cameras, and geometry to nodes to create visible content.

Reference:

https://developer.apple.com/documentation/scenekit/scnnode