What is Cucumber , It's working structure?

1.Cucumber is a high-Level Testing framework that supports behavior driven development.

2.It runs automated acceptance tests on web applications.

3.A Cucumber is a tool that executes plain-text functional descriptions as automated tests. 

    The language that Cucumber understands is called Gherkin.

Cucumber Working structure:-

Features Introduction:-

Every .feature file conventionally consists of a single feature. A line starting with the keyword 

Feature following by free indented text stars a feature. A feature usually contains a list of scenarios. Scenarios together independent fo your file and directory structure.

Example:-

1) Given: - The login page is opening ( what software will look like to user)

2)  When: - I input username and password and click the login button.(Things that the user will do)

3) Then: - I am on the home page 9 what the user should expect)