A route through a task
To return an item, a customer might open an order, choose a reason, select a refund method, and confirm the request. A user flow shows these steps and the choices between them, such as what happens if the item cannot be returned or the customer is signed out.
The simplest successful route through a flow is sometimes called the happy path.
Teams often draw a flow before designing each screen. They can then make a prototype and ask people to try the task. The flow helps people designing and building the product agree on the full task.
Cover the whole task
A useful flow also shows errors, ways to go back, what happens if someone lacks access, and what they see at the end. A flow is a plan. Usability testing and analytics can reveal where the real experience differs.