From Support

Widget Boxes are containers which hold one or two Widgets. A Widget Box itself does not usually have any borders or background to distinguish it on the site. These boxes can be converted at any time into 1 Cell or 2 Cells. You are not allowed to delete the last remaining Widget Box on your site.

When deleting a Widget Box, all Widgets contained therein will be deleted, along with their settings. When converting a Widget Box into 1 Cell or 2 Cells, the following choices are made:

• When converting a one-celled Box into a two-celled Box,
  • If there is no Widget present, the conversion is made.
  • If there is a Widget present that has a half-size equivalent, the Widget is converted and your widget settings are transferred.
  • If there is a Widget present that does not have a half-size equivalent, a message is displayed alerting you of the issue. If you proceed with the conversion, the Widget will be deleted along with its settings.
• When converting a two-celled Box into a one-celled Box,
  • If there are no Widgets present, the conversion is made.
  • If there is one Widget present (left or right side makes no different), the Widget is converted into its full-size equivalent. All Widgets have a full-size equivalent!
  • If there are two Widgets present, a prompt is displayed asking you which Widget should be converted. The other Widget is deleted, along with its settings.

All Widget Boxes start one-celled and empty. All Widget Boxes have a minimum height of 20px.