Behaviour Driven Development (BDD)

Behaviour Driven Development is an agile approach to delivering software with the goal of the developers, testers and product owners or business analysts collaborate to have a shared understanding of intended behaviour through examples. These examples can then be formulated into test scenarios and automated to provide evidence that the desired behaviours are implemented and working successfully. These automated test scenarios are typically written in a human readable format known as Gherkin. The three phases of BDD are Discovery, Formulation and Automation. 

Note that tests written in Gherkin are not inherently BDD test cases as this requires completion the Discovery and Formulation phases.

Behavior-Driven Development (BDD) is an agile software development methodology that improves communication and collaboration between technical and non-technical team members by focusing on system behavior from the user's perspective, rather than on the technical aspects of the implementation.

A software development approach that uses plain, structured language to describe the expected behaviour of a system, typically in Given-When-Then format. BDD encourages collaboration between developers, testers, and non-technical stakeholders by expressing requirements as concrete examples of how the system should behave. 

Even when BDD is not used to generate automated tests, the practice of writing behaviour-based examples at a refinement stage can guide manual testing and surface gaps in acceptance criteria before development begins.