This section provides a clear and concise explanation of the difference between pure functions and side effects, with practical examples to illustrate both good and bad practices. The examples are especially effective in demonstrating why pure functions are preferable—highlighting predictability, testability, and ease of refactoring. The "bad" code block effectively showcases common pitfalls like mutating external state, while the "good" example demonstrates clean and functional code by returning new values instead of modifying existing ones. The added inline comments are helpful for reinforcing key points. Overall, this is a solid addition to your documentation or GitHub README—well-structured, informative, and easy to understand.