BDD is an approach that synthesizes test-driven development and acceptance test-driven development by describing features in natural language. It involves defining features using a Given-When-Then structure to describe scenarios and benefits teams by helping gain knowledge of the business domain, improve understanding of functionality, enable collaboration, provide documentation, and structure tests. However, BDD may not be needed if management does not prioritize testing, assigns testing responsibility only to QAs, and does not understand the purpose of automation or allow time for code refactoring.