**36. What is Tree traversal algorithm ?**

Tree traversal is the process of visiting each node in a tree, such as a binary tree or binary search tree, exactly once. There are several effective traversal algorithms which we will cover below.

**37. What are the tasks performed during preorder traversal ?**

A pre-order traversal on a tree performs the following steps starting from the root:

Return the root node value.

Traverse the left subtree by recursively calling the pre-order function.

Traverse the right subtree by recursively calling the pre-order function.

**38. What are the different binary tree traversal techniques ?**

Preorder traversal

Inorder traversal

Postorder traversal

**39. Properties of Binary Tree ?**

Trees are used to represent data in hierarchical form.

Binary tree is the one in which each node has maximum of two child- node.

The order of binary tree is ‘2’.

Binary tree does not allow duplicate values.

**40. What is a full binary tree ?**

A full binary tree (sometimes proper binary tree or 2-tree) is a tree in which every node other than the leaves has two children. A complete binary tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible.