BDD is a software development methodology that extends TDD by focusing on application behavior from the end user's perspective using natural language specifications.

Key Differences:

• TDD: Write test → Write code → Refactor (code-focused)
• BDD: Define behavior → Write scenarios → Implement step definitions → Write code (behavior-focused)

BDD Benefits:

• Uses "Given-When-Then" format readable by non-technical stakeholders
• Promotes collaboration between developers, testers, and business analysts
• Creates living documentation that stays current with implementation
• Focuses on user value rather than technical implementation