A QuarkXPress project file can contain multiple layouts (for more information, see "Projects and layouts" in A Guide to QuarkXPress ). When you create an App Studio layout, QuarkXPress creates a separate layout for each device/orientation combination you checked in the New Project dialog box. All of these layouts are members of a single layout family .
A layout family displayed in split view. Each tab across the top represents a layout that is part of the layout family.
A layout family is a group of layouts that represents a single App Studio article. One layout family might include a horizontal layout for the iPad, a vertical layout for a different type of tablet, and both vertical and horizontal layouts for a third type of tablet. All of the layouts in a layout family are bound to one another in terms of page count; if you add or delete a page in one of a layout family's layouts, that page is added or deleted from all of the layouts in the layout family.
Layout families make it easy for you to keep content synchronized between the various editions of each page of content. For example, assume that you're working on a 30-page issue, and you discover that you need to add a new page after page 12. You can go to any of the layouts in the layout family and add the new page, and the page is automatically inserted in every other layout in the layout family. This is much easier than manually adding the new page to each layout one-at-a-time.
When you create a layout family, QuarkXPress displays the project in a split view. You don't have to work on the layout in split view, but it can be helpful when you're trying to keep different editions of a page consistent.
Another helpful feature for App Studio issues is the shared content feature. This feature lets you put copies of a picture or a chunk of text into different layouts, and then automatically keep the copies synchronized. So, for example, if you correct a name on page five of one layout, the name can be automatically corrected in all of the other layouts too. For more information, see "Working with shared content" in A Guide to QuarkXPress and " Synchronizing content between orientations ."