Cucumber is a tool to support Behavior Driven Development with plain text specifications and unobtrusive automation in Ruby. The text is written in a business-readable domain-specific language and serves as documentation, automated tests and development-aid – all rolled into one format. This short video shows how you can get started in two minutes flat, using only two files: a simple feature file, and a few lines of ruby to execute it.
Video source: http://chrismdp.com/2012/10/the-simplest-cucumber-project/
Further reading: Cucumber Presentation