If you use PowerPoint in your classroom you will notice the change to the Presenter View.
Basically this lets you use two monitors (your laptop and the projector) - one is what your audience sees, the other gives you an enhanced set of tools.
It does look different and you'll need to have a little practice.
This view can cause issues if you use hyperlinks in your presentations - click on the link and it will show on your laptop - but not on the screen.
You can work around this in two ways.
1. In this view you are basically operating in extended desktop mode. If you ensure that the browser window is open on the extended screen (in this case the projector) it will work fine.
2. You can change the display settings by clicking here and selecting Duplicate Slide Mode.
If you don't want to do this each time you use a PowerPoint simply click on the Slide Show ribbon and uncheck "Use Presenter View"