In Microsoft Publisher, page size refers to the size of your publication, not to the paper, or sheet, size used for printing. Page orientation refers to the portrait (vertical) or landscape (horizontal) layout of the publication.
Any publication layout you select in Publisher includes the page size and orientation most often used for that particular type of publication. You can easily change page size and orientation and preview your changes in the Page Setup dialog box.
Note To change the paper, or sheet, size and orientation, click the Printer & Paper tab.