A user scenario is a narrative description that outlines how a specific user persona interacts with a product or service to achieve a specific goal. It focuses on the motivation, context, and actions of the user, rather than the specific UI details.
Scenarios provide context. A feature might work technically, but fail in the real world because it ignores the user's environment or emotional state. Scenarios force designers to consider the "why" and "when," not just the "how."
We write scenarios like engineers write integration tests. A scenario defines the initial state, the trigger, the sequence of actions, and the expected final state. This rigor ensures that we are solving complete workflows, not just isolated interactions.