How to Work with Slide Layouts in PowerPoint
While every theme comes complete with its own set of professionally designed layouts, you may want to change them a bit to better suit your needs.
Any changes you made to the layout in Slide Master view are applied to all the presentation slides based on that layout.
You can also create a brand-new slide layout if you need something unique.
Where you place the slide here determines where it appears in the menu when inserting or changing a slide layout in Normal view.
The new layout is now available in the Slide Layout menu on the Home tab.