These effects control how an object leaves the slides. When you apply this effect and run your show, your object will perform this effect at the specified time.
These effects control what the object does while on the slide.
Then, and only then, will your object “enter” the slide at the time you specify. When you apply this effect and then run a slideshow, your object will not appear until this effect plays. These effects control how an object enters the slide. No matter the object, be it text, a picture, or shape, you only have three basic “states” or effects that you have to worry about creating or applying to your object.