# All About Binary Tree (BT)

# Binary Tree 
Binary Tree is one of the starting part of non-linear data structure, it is one of the key concepts of Data Structures. In Binary Tree data is stored in Hierarchical order. Binary Tree  is defined as a Tree data structure with 2 nodes right or left along with the data element. Each node have at most two nodes left or right. 

## Why we study?

The reason is Sorting. Binary search trees, a variant of binary trees are used in the implementation of sorting algorithms to order items. A binary search tree is simply an ordered or sorted binary tree such that the value in the left child is less than the value in the parent node.

![binary-tree-to-DLL.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1665682416093/p9PwMX-x4.png align="center")
In binary tree there is no guarantee of sorted data which means, sometimes data stored in sorted manner or sometimes not, it's totally depended on the way of insertion.

# Types of Binary Tree

1. Balanced Binary Tree
2. Full Binary Tree
3. Perfect Binary Tree
4. Complete Binary Tree
5. Degenerate Binary Tree and **many more**...

# Terminologies associated with Binary Tree

1. Root
2. Node
3. Parent - The node who have a sub-node of its own.
4. Child - Who came from the other node. 
5. Leaf Node - The node who doesn't have any child.

Traversals are the key point of Binary Tree, if you have **knowledge **about traversals in Binary tree then you can solve any problem related to Binary Tree with some own logics. 

### Some famous Traversals which have major role: 
1. In-order Traversal 
2. Preorder Traversal 
3. Post Order Traversal
4. Vertical Order Traversal 
5. Morris Traversal 

**The catch on the above traversals is **preorder, in-order, post-order **as well as **vertical order **have space complexity is big o(n) but in the** Morris traversal** space complexity is big O(1) because Morris traversal work on the **Binary thread concept.

** If you learnt above points and concepts genuinely then you have to move forward and solve the famous questions on the various platform such as leetcode easily**.