Transitions are visual effects that play as you move from one slide to the next. For example, the Push transition makes a slide appear to push the previous slide off the screen.
Select a slide in the slide navigator.
In the Animate inspector, click Add an Effect.
Choose a transition.
The transition automatically previews on the slide.
Specify transition options, such as duration and direction, using the controls in the Transitions pane.
If you choose to have a transition start automatically, it begins playing immediately after you advance the slide.
If you want to apply the same transition to multiple slides, apply the transition to a single blank slide, then duplicate that slide multiple times. When you add content to the duplicated slides, the transition is already in place.
To remove the slide transition, click Change in the Transitions pane, then choose None.