1.1 What Is a Hierarchy?
A hierarchy is a transform-based relationship between two or more objects, or transform nodes. One object is known as the “parent,” and the other object is known as the “child.” Two objects connected to the same parent are known as “siblings.” You can have as many objects in a hierarchy as you wish, and parents can have multiple children, but a child object can only have one parent.
Hierarchies are very prominent in computer-based systems, because they are instrumental in categorizing and organizing data. It’s also used in something much more commonly understood by the casual computer user—folders and files!
Folders and files are set up in a hierarchical manner, which is to say that you “put” files ...