The Slide Master is an extremely useful tool when creating longer presentations where you want a consistent appearance to all the slides. For example, suppose you wanted the text "Another great presentation from our creative people" to appear at the bottom of every slide, you could simply add it once to the Slide Master.
A single Slide Master sits behind all the other slides of the presentation rather like two panes of glass on top of each other, where the Slide Master is the bottom pane – anything written on the bottom pane is visible providing that the top pane has nothing on it to obscure it.
Select View/Slide Master - like a normal slide, you can now add and edit presentation elements.
The Slide Master has two special objects:
Title Area for AutoLayouts – this controls the size, location and appearance of all the titles in your presentation. When you modify this, all new slides that you insert using one of the built-in templates (that has a title) will take on the appearance of the Title Area of AutoLayouts. All existing titles are similarly affected.
Object Area for Autolayouts– as above, but this time affects the content area of your presentation.
Select View/Normal to return to main presentation.