You can merge any object that you create and place on a slide, including images, captions, click boxes, highlight boxes, text entry boxes, and buttons. Merging permanently removes the interactivity of the object, making it an image of the object.
The merging feature is useful in several situations. For example, suppose you import a large image into a slide that contains other objects. You can merge the image into the slide so that it becomes a static background for the other objects. You can also make text a permanent part of a slide by creating a transparent text caption and then merging the caption.