Roles are placeholders that will help you pre-assign fields to future recipients.
On the top right of your screen, click on Roles. Then, add one role for each person that should sign or receive the document. (i.e. Client, Sales Rep, etc.)
When you create a document from your Template, simply designate which recipient belongs to which role and their fields will automatically be assigned to them.
Role names are internal and visible only to your and your team members.
Then assign fields to your role(s) and that's it! When you create a document out of the template, you will assign actual recipients to roles which will automatically assign fields to the recipients.