binary search tree

Is a binary tree in which the keys in the left subtree are less than that of the root, and the keys in the rigth subtree a greater (or equal) to the root. And the subtrees are binary search trees.Using the Tree class, we can insert a node into an empty or non-empty tree. Using the Node constructor from the Node class, we can write the following non-recursive method:
void insert()
{
  Node newNode = new Node (item, null, null);

  if (root == null)
    root = newNode; // insert in empty tree
  else
    root.insert(newNode); // recursive insertion in non-empty tree

}

// recursive method to insert into a non-empty BST

void insert(Node newNode) 
{
 
 if (newNode.item < item)
   if (lchild == null)
     lchild - newNode;
   else
     lchild.insert(newNode);
 else
 if (rchild == null)
     rchild - newNode;
   else
     rchild.insert(newNode);
}