Gherkin

Gherkin is the language that Cucumber understands. It is a Business Readable, Domain Specific Language that lets you describe software’s behaviour without detailing how that behaviour is implemented. Gherkin serves two purposes – documentation and automated tests. -And a third bonus feature – when it yells in red don’t be offended – it’s talking to you, telling you what code you should write.

Gherkin’s grammar is defined in the Treetop grammar that is part of the Cucumber codebase. The grammar exists in different flavours for several Spoken languages, so that your team can use the Given-When-Then keywords (plus a few more) in your own language.