What are test scenarios and how do they differ from test cases?

A test scenario is a high‑level description of a functionality or a user story that needs to be tested. It outlines the purpose of the test and the conditions under which it should be executed. A test case, on the other hand, is a detailed, step‑by‑step set of actions, inputs, and expected outcomes that validate a specific scenario. In other words, a scenario defines the what to test, while a test case defines the how to test it. Scenarios are often used for planning and traceability, whereas test cases are used for execution. For example, a scenario might be “User logs in with valid credentials,” and the corresponding test cases would include steps to enter a username, enter a password, click the login button, and verify that the user is redirected to the dashboard. Scenarios help ensure coverage at a higher level, while test cases provide the granular detail needed for automated or manual testing.