SharePoint column controls
When you open Nintex Forms for a new SharePoint list, the form designer automatically creates form fields for the equivalent SharePoint columns in your list. The SharePoint columns are displayed in the designer when you open it. If you want to delete them from or add them to your form, you can do so under the SharePoint Columns controls.
For example, you create a SharePoint list which collects different types of data including the age entered in a field of your form. The Age column you add to your SharePoint list is of a Number Type, and includes a Minimum allowed value of 18. When you open the form designer, the form already has an "Age" Number control, which has a Minimum value of 18.

The form controls available in the SharePoint column group are the same types of form controls you can add to your form from the General group, except the SharePoint column Names replace the Titles of the controls, and some fields or settings are already configured because of the related column settings.

The columns in SharePoint lists have settings, which the forms designer inherits when it auto-creates controls in your form. If you want to edit a setting for a SharePoint column form field, then you must edit the equivalent list column setting.

Yes, you can delete the SharePoint column form fields that the form designer automatically adds to your form. If you want to add them back to the form they are available under SharePoint Columns controls.