The Design Tab and Applying Themes:
Design Tab:
The Design Tab allows you to change individual elements, rather than applying a general design to the whole presentation.
In the Design tab, there are a series of choices that allow you to change the look of your slide:
Themes:
Themes make a number of formatting choices for you, from font size and type, to background color.
Click the + sign to expand the menu. Click the topic to launch the player.