The Column Default
Each list type has an initial default set of columns. You can change the default set of columns by displaying the desired columns, then clicking the 
button or selecting Set as Default Columns from the View menu. This selection causes the set of columns, and their widths and positions, for the currently displayed list, to become the new default for that list type.
After you select Set as Default Columns, all new lists of that type, plus all existing lists of that type will now display the columns you specified as the default, except lists on which you have specified columns using the Column Selector.
Lists on which you had previously set columns using the Column Selector will continue to use the columns you specified until you explicitly change them again using the Column Selector, or you click the Use Default button on the Column Selector, which causes that particular list to use the currently set default.