A binary tree is a tree data structure in which each node has at most two children,
which are referred to as the left child and the right child.
A binary tree in C is a data structure in which every node can have a maximum of two children nodes.

Binary trees are often used to represent hierarchical data, such as the file system of a computer.
In a file system, each file or directory can be represented as a node in a binary tree,
with the parent directory being the parent node and the child directories being the child nodes.

Binary trees are also used in many other applications, such as:
* Sorting algorithms
* Searching algorithms
* Compression algorithms

In a binary tree:
1. Each node has at most two children, referred to as the left child and the right child.
2. The topmost node in the tree is called the root.
3. Nodes without any children are called leaf nodes or terminal nodes.
4. Nodes with at least one child are called internal nodes.
5. Nodes at the same level of depth in the tree are often referred to as siblings.
6. The path from the root to any node is called a branch or a path.
7. The depth of a node is the length of the path from the root to that node.

Binary trees are a fundamental data structure in computer science and serve as the basis for
more complex tree structures like balanced binary trees, AVL trees, and red-black trees,
which optimize various operations for specific use cases.