Behavior-driven development (BDD) is an outside-in development technique. BDD encourages capturing the requirements as a set of scenarios or use cases that describe how the end user will use the feature. The scenario will precisely express what will be the input supplied and what is the expected response from the feature. The best part of BDD is that it uses a domain-specific language (DSL) called Gherkin to describe the BDD scenarios.
Gherkin is an English-like language that is used by all the BDD test frameworks. Gherkin is a business-readable DSL that helps you describe the test case scenarios, keeping out the implementation details. The Gherkin language keywords are a bunch of English words; hence the scenarios can be understood by both technical and non-technical members involved in a software product or a project team.
Did I tell you that the BDD scenarios written in Gherkin languages serve as both documentation and test cases? As the Gherkin language is easy...