Binary Tree/Search Tree

Question

I'm beginning to start data structures and algorithms in Python and I am on Binary trees right now. However I'm really confused on how to implement them. I see some implementations where there are two classes one for Node and one for the tree itself like so:

class Node:
    def __init__(self, data):
    self.right = None
    self.left = None
    self.data = data 

class Tree: 
    def __init__(self):
    self.root = None
    
    def insert()
    def preorder()
    .
    .
    .

However I also see implementations where there is no Node class and instead all the code goes inside the Tree class without the following

def __init__(self):
    self.root = None

Can someone please help me understand why there are two different ways, the pros and cons of each method, the differences between them and which method I should follow to implement a binary tree.

Thank you!