Is the root node an internal node?

Question

So I\'ve looked around the web and a couple of questions here in stackoverflow here are the definition:

• Generally, an internal node is any node that is not a leaf

Answer 1

Yes root node is an internal node.
[More explanation]

A root node is never called as a leaf node even if it is the only node present in the tree. For ex. if a tree has only one node then we say that it is a tree with only root node, we never say that the tree has a single leaf node.
Since internal node means a non-leaf node and because root node is never considered as leaf node I would say that in case of single node tree root node is an internal node.