Gherkin
In plain terms
A plain-language syntax for describing software behavior.
Going deeper
Gherkin uses Given-When-Then structure to specify scenarios in readable language that both humans and BDD tools understand. It's the language of executable specs.
Under the hood
Each scenario becomes an automated test via step definitions; readability is its main value.
Examples
Cucumber, BDD, Given-When-Then, acceptance criteria, SpecFlow.
Think of it like...
Like a screenplay describing exactly how a scene should unfold.