You can edit the layout of your subpages by clicking on the “Subpages Layout” tab while you are editing your homepage. The boxes show a representation of the structure of your subpages. Different pieces of information on your subpages are represented by simple blocks that you can edit and move around.
Your subpage layout is composed of a Main Content area, a header, a footer, and either one or two columns (These vary depending on what template you have chosen). Your header and footer are shared across all your pages, and other content is shared only across your subpages. Just like your homepage, you can choose what widgets you want to go in the columns, and add, move, and remove them as you see fit. These will show up on every page of your website, with a few exceptions. Some website pages like Map Search have extra wide content that can replace the third column.
For more information, please see Editing Your Homepage.