What is TDD (Test-Driven Development) is a software development approach where developers write tests before writing the actual code. The process follows three simple steps: write a test, write just enough code to pass the test, and then improve the code.

What is TDD helps developers write cleaner code because it forces them to focus only on what the code should do. Since the test defines the requirement in advance, developers avoid adding extra or unused logic. This results in simple, well-structured, and easy-to-read code.

What is TDD also improves code clarity by encouraging small, focused functions. Each piece of code is written to pass a specific test, which naturally keeps the code modular and easier to maintain. Over time, this reduces complexity and makes the codebase more reliable.

In short, what is TDD is a practical method that helps developers write clean, organized, and maintainable code while reducing bugs and rework.