BDD lets organizing software development documentation in a more efficient, more business-like way. Thus business analysts can access information needed much faster and stakeholders see changes implemented much better. Unlike TDD BDD introduces additional details in unit tests.


BDD is an extension of Test-Driven Development (TDD) that emphasizes developing features based on a user story and writing code that provides a solution to real problems.



BDD is largely an extension of the TDD methodology. The developer defines a test case, tests code to verify that the test case will fail. Next, the developer writes the code necessary to pass the test case and then tests the code to ensure compliance.

Where BDD differs from TDD is how the test case is specified. 

BDD tests cases exist in a way that specifies the desired behavior.
The clear language of BDD test cases makes it simple for all stakeholders in a development project to understand.


TDD is a developer-focused methodology that aims to encourage well-written units of code that meet requirements while

ATDD is a methodology designed to promote collaboration among customers, development, and QA to ensure well-designed requirements.

Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle:
first the developer writes an (initially failing) automated test case that defines a desired improvement or new function,
then produces the minimum amount of code to pass that test,


Is TDD agile?

Agile is a philosophy whereas TDD is a specific methodology.