The Divider field can be found under Media & Structure section. Its role is to provide a structure to your form. You could use it to separate different section of the form in order to make it easier to scan by your respondents.
Note: the divider field does not count against the total number of fields you can use according to your pricing plan.
Once you add your divider field on your form, on the right side panel you will be displayed different customization settings.
You can choose to change the style: either make it a straight line or a dotted line. Another setting would be the thickness of the divider field.
If you want to make the divider shorter, you can choose a lateral padding, either medium or large.
If you want to bring more space between the divider and the above and below fields, you simply have to apply a vertical padding: either medium or large.