What is the difference between a use case and a user story?

Question

Accepted Answer

**Use Case** — detailed functional specification. **User Story** — brief requirement in user voice.

**Use Case:**
- Detailed description.
- Actors, preconditions, flows.
- Alternative and exception flows.
- More formal.

```
Use Case: "Login"
- Actor: User
- Precondition: User has account
- Main Flow: Enter credentials → Validate → Grant access
- Alt Flow: Invalid credentials → Show error
```

**User Story:**
- Brief format.
- "As a [role], I want [feature] so that [benefit]".
- Less formal.
- Accompanied by acceptance criteria.

```
User Story: "As a user, I want to login so that I can access my account"
Acceptance Criteria:
- Given valid credentials, when I click login, then I see dashboard
- Given invalid credentials, when I click login, then I see error
```

**Key differences:**
- **Use Case** — detailed, formal.
- **User Story** — brief, informal.

Systems Analyst: What is the difference between a use case and a user story?