Hidden Slides, as the name suggests, are slides that will not appear in your presentation but are still part of your presentation. They might be slides that you had put in your presentation but later choose to hide because you foresee time limitations, or they might be slides containing statistics to back up a claim in your presentation.
Go to the slide you wish to hide then go to the Slide Show Ribbon, and click on the Hide Slide icon in the Set Up Group.
Now it will be hidden during your presentation unless you specifically navigate or link to it – if you are in Normal View (seeing the slide and smaller versions of the slides on the left of the screen) you should notice that the hidden slide has a line through the number and seems a little grayed out.
The Slide Sorter View is convenient if you are hiding multiple slides at a time; here hidden slides display with a gray hash mark through the slide number.
To go to a hidden slide during your presentation, right-click anywhere on the current slide, choose the Go to Slide option, and then pick your hidden slide. The hidden slide will have parentheses around the slide number.
When you show a Hidden Slide and then click or press the spacebar to advance to the next slide in the sequence, it will jump to your next “real” slide, not the next Hidden Slide (even if one happened to be next).