When you switch to Slide Master View in PowerPoint 2013, an entirely new tab appears on the Ribbon. This new tab is appropriately called Slide Master.
Here’s a quick overview of each group on this tab and the controls found in them:
Edit Master: The controls in this group let you edit the Slide Master. You can use the Insert Slide Master button to create a new Slide Master, or you can use the Insert Layout button to add a new layout to an existing Master. You can also use the Delete and Rename buttons to delete or rename Masters or layouts.
Master Layout: The controls in this group let you edit a layout by adding or removing placeholders, the title, and footer elements.
Edit Theme: The controls in this group let you apply a theme to a Master or a layout.
Background: The controls in this group let you set the background for a Master or a layout.
Page Setup: The control in this group lets you change the orientation for a page. (Unfortunately, PowerPoint doesn’t allow you to have Masters with different orientations in a single presentation. When you change the orientation of a Slide Master or a layout, the orientation of all Masters and layouts in the presentation is changed.)
Size: The control in this group lets you select Standard, Widescreen, or a custom slide size.
Close: This group contains a Close Master View button that returns you to Normal View.