If you have multiple slides you can choose the effects individually for each slide or if you want to apply the same animation/transition effect to your entire PowerPoint presentation, you can also do that. You can also add effects (Animation Styles) via the Animations tab. When the presentation is played in slide show mode, your audience will see the applied transition between the slides. When you start building your slides, you can add new effects from the Transitions tab. Usually, users start with a blank PowerPoint presentation file or a ready-made template with no effects. For example, you may choose to use cool animations for PowerPoint like Cover effects, Blinds effect, Shape Diamond effect, Wheel effect, etc. In PowerPoint 2007, 20 there are many already defined animated effects that you can use from within the Animations or Transitions tab.
How To Add Transition Effects in PowerPoint