Need a little understanding about the side boxes

To shut off sideboxes I change the setting at admin>config>layout-settings>column-left/right-status.
This same area has settings to change the width of the boxes also.

To leave the columns on the page but just remove the boxes I go to admin>tools>layout>boxes>controller. This is the aera I need some understanding of.
The first column, "left/right column status" turns off a particular box by changing the setting in the column to either off or on.
The second column, "left or right column" lets you choose which side of the page you want the sidebox on.
The third and fourth columns have to do with sort order. The higher the number, the lower down the page the sidebox appears. But I do not understand what is meant by "left and right column" and "single column".
The fifth column, "single column status" is also a mystery.

Can anyone explain 3,4 and 5?

This same area has settings to change the width of the boxes also.
No, that is in
config > layout settings
But I do not understand what is meant by "left and right column" and "single column".
Some have a 3 column layout left & right
Some have a 2 column layout Left OR right
Some have no side columns or single

The "single column" setting is not actually used for any sideboxes currently, except for the search_header box which appears in neither side. So for nearly all sideboxes, you just enable or disable for left & right, and determine which side it goes on by the sort order location in the main part of the admin page.