Doesnt this contradict?(c++) BST is made by comparing strings

For preorder, the root would be Apple with left child banana and right child cat. How is banana smaller than apple?

And in inorder, the root would be banana, left child apple, right child cat

For postorder, the root is apple, left child cat, right child banana.

How does this make sense? The root for each order is different

21:16 learn.z zyBookse 2 2. Remove 3. Print 4. Search 5. Smallest 6. Largest 7. Height 8. Quit Preorder apple(2), banana (), cat (). anana (3), cat (1), Inorder apple (2), banana (3),cat (1) Postorder-cat (1), banana (3), apple (2) Enter menu choice: 1. Insert 2. Remove 3. Print 4. Search 5. Smallest 6. Largest 7. Height 8. Quit Enter string to remove: Enter menu choice: 1. Insert 2. Remove 3. Print 4. Search 5. Smallest 6. Largest 7. Height