When you develop a slide show, you might want to include some special effects as you make the transition from one slide to the next. When a new slide appears, your audience sees a transition effect—for example, a dissolve, a checkerboard, a "newsflash" effect—and/or a sound. You can also specify whether you want the next slide to advance automatically after a preset time or whether you want to switch to the next slide manually with a mouse-click.
On the Animations tab, point to the various transitions to see how they look, and then click the one you want.
Specify how you want to advance to the next slide. If you want the slide to advance automatically, specify how long each slide is to be displayed before it advances.
Click Apply To All if you want all the slides in your presentation to have the transition you just selected. If you don’t want the same transition for all the slides, repeat steps 1 through 5 to add transitions to the other slides in your presentation.