1- Root: Node with no parent
2- Edge: Link from parent to child
3- Leaf: Node with no children
4- Sibling: Childern of same parent
5- Ancestor: means parent,grandparent,great grandparent and so on
6 -Depth of a node: Length of the path from root to node
7 -Height of a node: Length of path from node to deepest node
8 -Height of a tree: Same as height of root node
9 -Depth of a tree: Same as Depth of root node.
10- Predecessor of a node is the immediate prev node in inorder traversal of the binary tree
11- Successor of a node is the immediate next node in inorder traversal of the binary tree