When you add placeholders to a layout, if the content in those placeholders changes the purpose of the layout, you'll want to rename the layout.
On the View tab, in the Master Views group, click Slide Master.
In the pane that contains the slide master and layout thumbnails, right-click the layout thumbnail that you want to rename.
In the Rename Layout dialog box, in the Layout name box, enter the new name of the layout, and then click Rename.
On the Slide Master tab, in the Close group, click Close Master View.
Note: If you apply a slide layout to one or more slides in your presentation, and then you edit that layout, you must reapply the updated layout to the slides so that the slides reflect the edits. For more information about editing and reapplying a layout, see Edit and reapply a slide layout.