TDD is a software development method where tests are written before the actual code. In the TDD approach, developers first create a small test for a feature, then write just enough code to pass that test, and finally improve the code while keeping all tests working. In simple terms, what is test driven development means building software step by step with testing as the base. In TDD development, this cycle helps catch errors early and ensures each part of the software works as expected. The benefits of TDD include cleaner code, fewer bugs, easier updates, and better confidence in changes. Key advantages of test driven development are improved code quality, faster debugging, and more reliable software over time. Conclusion: Test-Driven Development focuses on writing tests first and code second. By following the TDD approach, teams build stable, well-tested software with fewer issues and better long-term quality.