what do you mean by Preorder Traversal in tree?

Problem statement: what do you mean by Preorder traversal in tree?

• Preorder traversal is defined as follows:

1. visit the root
2. traverse the left subtree in preorder
3. traverse the right subtree in preorder 

• Recursive Preorder Traversal:

1. void  PreOrder(BinaryTreeNode root){
2. if(root !=null){
3. System.out.println(root.getData());
4. PreOrder(root.getLeft());
5. PreOrder(root.getRight());
6. }
7. }