A master slide is basically a template for your presentation. It might have
a background image on it, use specific fonts and colors, and have footer text
that you want on every slide. Some companies will put their logo in the
corner of every slide. Here's where the difference between a master and a
regular slide comes into play. On a master, you paste the logo in the
corner, and that's it. It'll appear on every slide. Without a master like
that, some people paste that image on each and every slide.
To see examples of them, just create a new presentation on your computer and
choose a design template. Do View>Master and try changing some of the fonts.
