Page layouts help set the look of your page in all device screens. Pages are divided into main and sub content (Except layout 12 which is a one column only layout). Main content always moves to the top when the screen size necessitates stacking content. There are ten two-column layouts, five with main content on the right and five with main content on the left. Columns are 1/4, 1/3, 1/2, 2/3 or 3/4 page widths. Layout 11 has stacked main and sub content. In the admin section you select which column to put any gallery, videos, links list or audio player you may use.
A wider content section is good for larger block-quotes
This layout's wider sub content column makes it easier to add text and other content. Image and video galleries scale down to smaller columns.