"Tell a me story."
|--Every child at some point|
The story is the unit of functionality in an XP project. We demonstate progress by delivering tested, integrated code that implements a story. A story should be understandable to customers and developers, testable, valuable to the customer, and small enough so that the programmers can build half a dozen in an iteration.
A user story is a chunk of functionality (some people use the word feature) that is of value to the customer. It provides a simple way for developers and customers to chop up what the system needs to do so the system can be delivered in pieces.
The emphasis ...