Can you explain what the given-when-then pattern means and how it is used in testing?

The given-when-then pattern is a structure for describing test cases that helps clearly define conditions, actions, and expected results.

• Given — initial conditions or context (e.g., user is logged in).
• When — the action performed (e.g., user clicks a button).
• Then — the expected outcome (e.g., a success message appears).

This pattern is often used in BDD (Behavior Driven Development) to improve understanding of requirements and automate tests. In Java, it can be applied using frameworks like Cucumber.