1)	Root: top node of a structure
Child: nodes lower then another in the hierarchy
Leaf: one of the bottom nodes
Parent:  element (node) higher then another in the hierarchy 
Ancestor: a node somewhere earlier in the path for a given node
Sub-tree: tree inside the main tree

2)	 You need 17 levels to store 100,000 nodes.
3)	The max and min: a) 1-min and 15 max
                  b) 7 min and 7 max
       8)	It counts leaves on a tree