When you have objects overlapping on a slide, it may be difficult to select the object you want. For example, you may find yourself selecting the text placeholder when you want to select an image. But when you move the text placeholder to select the image, getting the placeholder back in its exact location is difficult.
Instead, select any object and press the Tab key. PowerPoint selects another object on the slide. Continue to press the Tab key as PowerPoint selects object after object until the object you need is selected.