In general, you can quickly switch between several different view states (normal view, slide sorter view, slide show) using the view buttons in the lower left corner of the screen. But I'm afraid you don't know. Using the keyboard to match the View button can also achieve a completely different effect.
If you click the Normal View button, you can switch to slide master view if you press the SHIFT key, and then click the Normal View button (without pressing the SHIFT key) to switch back. If you click the Slide Sorter View button, you can switch to handout master view by pressing the SHIFT key.
In addition, you can have PowerPoint display thumbnails of slides in the upper-left corner of the screen so that you can preview the results when you edit them. To achieve this, you need to go to normal view and then select the first slide you want to show. Hold down the CTRL key and click the Slide Show button. You can click the slide thumbnail to change the slice, just as you would for a Full-screen slide show.
If you want more options, you can press and hold the Ctrl+shift key combination, and then press the various view buttons: ctrl+shift+ The Normal view button closes the left marker area and notes page and expands the slides to the available space. ctrl+shift+ the Slide Sorter view button to display the presentation as outline mode; ctrl+shift+ the slide Show button opens a set Up Show dialog box.