I presume you meant
Behavior-Driven Development (BDD)?
To put it short, to me BDD is "TDD done right." It's based on the idea that
you should be specifying desired behavior of objects rather than focusing on, for example, implementation details such as objects' internal state. Also, BDD puts a lot of focus in the kinds of terminology you use, trying to bring the specifications (tests) closer to the business domain in their vocabulary.
These are all things I consider being part of TDD when it's applied well.