binary trees binary trees if every node in tree can have at most two childrenthe tree is called binary tree in this we'll focus on binary trees because they are the simplest and the most common the two children of each node in binary tree are called the left child and the right childcorresponding to their positions when you draw picture of treeas shown in figure node in binary tree doesn' necessarily have the maximum of two childrenit may have only left childor only right childor it can have no children at all (in which case it' leafthe kind of binary tree we'll be dealing with in this discussion is technically called binary search tree figure shows binary search tree figure binary search tree note the defining characteristic of binary search tree is thisa node' left child must have key less than its parentand node' right child must have key greater than or equal to its parent an analogy one commonly encountered tree is the hierarchical file structure in computer system the root directory of given device (designated with the backslashas in :\on many systemsis the tree' root the directories one level below the root directory are its children there may be many levels of subdirectories files represent leavesthey have no children of their own