A React component under the Flux architecture should not directly modify any props passed to it, but should be passed callback functions that create actions which are sent by the dispatcher to modify the store. The action is an object whose responsibility is to describe what has taken place: for example, an action describing one user 'following' another might contain a user id, a target user id, and the type USER_FOLLOWED_ANOTHER_USER[23]. The stores (which can be thought of as models) can alter themselves in response to actions received from the dispatcher.