Binary Tree vs BST
A binary tree only restricts each node to at most two children. A Binary Search Tree adds an ordering constraint between a node and its subtrees. Therefore, every BST is a binary tree, but not every binary tree is a BST.
Binary Tree: Structural constraint only.
BST: Structural constraint plus value ordering.
Binary Tree inorder traversal is not necessarily sorted.
BST inorder traversal is sorted under the standard ordering rule.
BST supports efficient ordered searching when balanced.