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**A Binary Search Tree (BST)** is a special kind of binary tree in which elements are arranged according to an **ordering rule**:

## Rule

For every node in the tree:

- all values in the **left subtree** are **smaller** than the node's value,
- all values in the **right subtree** are **larger** than the node's value.

## Example

```javascript
        8
       / \
      3   10
     / \    \
    1   6    14
       / \   /
      4   7 13
```

Here:

- for `8`, the left subtree `{1,3,4,6,7}` < 8,
- the right subtree `{10,13,14}` > 8.

## Main operations

- **Search** - O(h), where *h* is the height of the tree (O(log n) on average);
- **Insertion** - finds the correct place using the same rule and inserts the node;
- **Deletion** - requires carefully rebuilding the subtrees.

## Features

- Efficient when the tree is **balanced** (search in O(log n)).
- When unbalanced (for example, if data is inserted in increasing order), it turns into a **list** - complexity O(n).

## Summary

**A Binary Search Tree** is a structure that stores data as a tree with a strict ordering,
which lets you **search, add, and remove elements quickly** compared to linear structures.

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