How do I adjust columns sideways?

This setting is used to adjust columns sideways to change the order of columns (visually). The order of columns is usually printed in the order shown under Content.

If you have a design with Left menu, centre column and right column, the content is printed in that order.

The reason you want to do this is to have different appearances for a computer visitor and a mobile visitor. For a computer visitor, you might want a standard design with a right column. However, for a mobile visitor with limited space, this means that the right column will appear at the bottom (if the information is stacked). If there is important information in the right column, you can adjust this information sideways so that it appears at the top.