Used in excess, they can be distracting and irritating. Transitions are used between slides. They include fades, cuts, and various elaborate effects.
Build effects occur within a single slide.
They are used to add bullet points one at a time. The points can appear from various directions with various flourishes. Both transitions and builds can be added one slide at a time, to a group of slides, or to the entire slide show. To add transitions or builds to the entire show, choose Select All from the Edit Menu. To add transitions or builds to a single slide, select the slide by clicking once on it.