The final step is for your Product Owner to define the Sprint Goal, an overarching objective that can be met by the Development Team that should provide them with guidance on why they are building the next increment.
It should be a short statement, such as, "Implement a simple checkout that allows credit cardholders to purchase items in their cart".
Try to keep your Sprint Goal concise, as this will help your team focus on building the right thing. The Sprint Goal should help you decide if our work is contributing to the outcome your Product Owner is seeking. One thing it should not be is a "laundry list" of work, or even a list of User Stories that your team needs to complete.