Any form fields that are made required fields are mandatory for the person working on the workflow run or filling out a form to complete before they can move onto the next task or step.
If there are parts of your workflow run that you must have filled out to ensure you have captured all the critical information, you can create required form fields.
If there are any fields in your form that may be necessary information for you to receive from your customers, you can make those fields required.
Workflows