What is a user story?

• A. A feature of an application; can be large or small
• B. An increment of time, also known as a sprint
• C. A high level estimate of the amount of work a team can complete in a sprint
• D. Smallest unit of work that creates a functional part of the application

Answer: (D)

A user story is a small, user-focused piece of functionality that delivers value when completed. It’s written from the user's perspective and is small enough to be implemented and tested within a single sprint, resulting in a functional part of the application for the user. That’s why describing it as the smallest unit of work that creates a functional part of the application fits best: it captures the idea of delivering concrete value in a manageable chunk. For example, a story might express: “As a user, I want to reset my password so I can regain access,” which is a discrete, testable piece of functionality that delivers real value. The other options describe a feature size, a sprint, or a velocity estimate—concepts that aren’t what a user story is.