TDD

Test Driven Development (TDD) is a development strategy in which developers write tests before writing the bare minimum of code required for the test to be passed. The process involves three stages: red, green, and refactor. In the red phase, a test is written which initially fails (since the code it's testing doesn't exist yet). In the green phase, the minimal amount of code to make the test pass is created. Lastly, in the refactor phase, the written code is improved without affecting its behavior. The process is often visualized as a cycle: "Red - Green - Refactor". This repeating process allows for smaller, more defined feature development, reduces bug emergence, and encourages simple design. TDD is primarily used in agile development environments.