Master pages specify the layout and background for the form design. You add objects that will occupy the same position throughout the form design on a master page. The Master Pages tab is hidden by default.
A typical form design that has two pages with different dimensions contains at least two master pages, one for each page. If a form design has multiple pages that have the same dimensions and orientation, the form design needs only a single master page.
You can start designing pages immediately with the default master page. If your design is more complex (for example, you need to create design components such as page headers and footers), it is best to work with those components directly on the master page.
You can place objects anywhere on a master page. Each master page can have a unique design, which you can apply to one or more pages. Master pages save you the effort of creating the same layout directly on individual pages, one page at a time. If several pages that have the same layout also need the same set of objects (for example, a standard footer), placing and maintaining one set of those objects on a master page is more efficient than duplicating the objects on every page. When the objects are placed on a master page, all associated pages display those objects in the background. Changing the master page after automatically updates all associated pages.
Use the Pagination tab to indicate whether the master page is used in odd (front), even (back), or blank pages and its placement in the page set. You can also choose whether pages that are rendered according to the selected master page should contribute to the total page count.
If you choose to place objects on the master pages, you might also want to adjust the sizes and positions of content areas, and create single- or double-sided features (such as headers and footers) to display across all pages.
Use the Master Pages tab to view, add, and delete master pages. You can also rename master pages, select the size and orientation of master pages, and reorder their sequence.
See also 

About master pages