You may not know it, but every time you apply a new design template to your slides, a slide master comes into your life. Well, make that a pair of masters — because a slide master typically comes in with a related title master.
How do the masters relate to the template?
The masters contain and reflect all the style elements used in the design template you've applied. These elements include font and paragraph styles; the position of your titles, text, and footers on the slide; the color scheme; and the background design. You get two masters because every template has one general set of styles for your slides, and a variation on those styles for your title slide, or slides, in the show.
The slide master and title master for the design template hang around behind the scenes, and you might never have a reason to open them up. (They live in master view; more about that, next section.) However, if you want to make the type of design changes we've described, the masters are where you go.
Original design template remains intact
Once you've changed a master, the change persists within your slide show. The original file of the design template you applied, though, remains unchanged. (You can preserve changes to the masters in a new template file if you want to; for more on that, see the course Create your own template.)