In PowerPoint 2010, you can use the new Sections feature to organize your slides, much like you'd use folders to organize your files. You can use named sections to keep track of groups of slides, and assign sections to colleagues to make ownership clear when you collaborate. If you're starting with a blank slate, you can even use sections to outline the topics in your presentation," explains Microsoft.
Take a look at this video to see how it works:
[Source: Office blog]