User flow illustrates a step-by-step way a potential user does from the very beginning of the website or the app to the very final interaction, reaching a particular goal. Therefore, it is based on the set of actions that are planned to be done by the user. Neither knowledge of real user experience and feelings conducted by existing clients previously nor a vast variety of solution levels are not included here.
It is done in the form of a block-scheme with graphical inclusions — wireframes, sketches, and gesture visualizing.
Use case clearly shows the main sense of solution the product offers, and helps make sure all the processes have their logical completeness.