Terminology

Node

A pythonic representation of data - each key in a dictionary is represented by a Node object. Node objects representing a dictionary "contain" (Nodes are created on-demand) other Nodes representing any keys in that dictionary.

Root node

This is your primary node - the one you initialize with file parameters and location (or a dictionary). The root node represents your main dictionary.

Child node

The root node spawns child nodes to represent all of the keys it contains. These child nodes can, again, spawn more nodes - but that does not make them root nodes.