What is an User Story ?

A concise, written description of a piece of functionality that will be valuable to a user (or owner) of the software.

• User Stories combine written and verbal communications, supported with a picture where possible.
• User Stories should describe features that are of value to the user, written in a user’s language.
• User Stories detail just enough information and no more. Details are deferred and captured through collaboration just in time for development.
• Test cases should be written before development, when the User Story is written.
• User Stories should be Independent, Negotiable, Valuable, Estimatable, Small and Testable.

User story description contains :

• Who (user role)
• What (goal)
• Why (reason)

• gives clarity as to why a feature is useful
• can influence how a feature should function
• can give you ideas for other useful features that support the user's goals