What is a feature file and what sections does it contain?

Feature: User account registration
  As a new visitor
  I want to create an account
  So that I can access member-only content

  Background:
    Given the registration page is open

  Scenario: Successful registration with valid data
    When  the user submits the form with valid details
    Then  a confirmation email is sent
    And   the user is logged in automatically

  Scenario: Registration fails with duplicate email
    Given a user account already exists with email "bob@example.com"
    When  the user tries to register with "bob@example.com"
    Then  an error message "Email already registered" is displayed

  Scenario Outline: Registration fails for invalid email formats
    When  the user submits the form with email "<email>"
    Then  a validation error is shown

    Examples:
      | email          |
      | notanemail     |
      | @nodomain.com  |
      | user@          |

Sections:

• Feature — one per file. A short title plus optional description (often a user story). Describes the capability being specified.
• Background — steps that run before every scenario in the file. Keep it short — only include context genuinely shared by all scenarios.
• Scenario — a single concrete example with its own Given/When/Then.
• Scenario Outline + Examples — a parameterised template that runs once per row in the Examples table.
• Tags — @-prefixed labels placed above Feature or Scenario to filter execution.

One feature file per feature area keeps things manageable. Files that grow to 10+ scenarios usually need splitting.