Slide masters are special slides that are templates of namely slides. It consists of two categories of objects: placeholders and non-placeholders.

Placeholder

Placeholders can provide format information, like position, size, color and so on, for objects, such as text, pictures, audio, and more. The format settings of placeholders are possibly inherited by slides, but their contents are not inherited. If a placeholder is with no-line style and empty, it has a dotted border. Different preset layouts provide different placeholders.

Non-placeholder

Non-placeholders are normal objects on slide master or layout. They will be regarded as background graphics of their derived slides, so they are read-only and not allowed to select on the slides. However, you can play audio and video objects during slideshow.