These fields are used to show the results of the calculator or display various types of content. You'll need a Formula field to show a calculation. If you also want to save the results make sure to add a Button field also.
Calculate something and show the result
Submit the calculator and/or send the user to another page
Show a text or even HTML content (including third party widgets like videos, calendars, etc) inside the calculator
Show an image inside the calculator
Group together multiple calculator fields and show them in one or more columns
If you need a multi-step calculator, place the Step Separator where you need the next step to start