As many as are necessary.
Microsoft Power Point is a presentation software. It can be used to create presentations or slides.
The purpose of presentation is to create slides. A slide can be used to present something interactively.
Editing a presentation.
A slide sorter is a feature or tool that is used in presentation software. It displays all of the slides as thumbnails in the current presentation.
You can easily set the time between slides manually. This could be done in the Power Point presentation 2011 version.
slides
You can only really actually work with one at a time. However, if you are using a Master Slide, you can affect all slides on your presentation. You can also do things to some or all of your slides in the Slide Sorter, like setting transitions. How many slides you can have will depend on the amount of memory you have, but it is not good design practice to have too many slides in a presentation.
You can set your defaults to specify either a portrait or landscape orientation for slides in a new presentation.
Personally, I'd say zero. When in a presentation, you should explain the viewers what's going on.
You can create as many slides needed for your powerpoint presentation, though when it comes over a hundred, the slides will appear bigger.
Slides.
A slide is a single screen of a presentation, and every presentation is composed of several slides. The slides contain the information you want to communicate with your audience.