Postorder Traversal of Binary Tree

Postorder traversal of a binary tree is a depth-first traversal method where the nodes are recursively visited in the following order: left subtree, right subtree, and then root. The steps are:

1. Traverse the left subtree.
2. Traverse the right subtree.
3. Visit the root node.

In a recursive implementation:

Postorder traversal is useful in scenarios like expression tree evaluation or deleting a tree.