PowerPoint is a presentation program developed by Microsoft. It is part of the Microsoft Office suite, and runs on Windows and the Mac OS X computer operating systems. The Windows version can also run on the Linux operating system, under the Wine compatibility layer.
Apart from the obvious paper-saving considerations, it has certain advantages over the use of traditional print-based texts, including, but not limited to, the novelty effect and the fact that it is a pretty standard format in business contexts.
For classroom activities it can be used for reading and writing exercises, as well as for specific activities based on giving presentations, and so on. Bear in mind, however, that attention span for a slide is 8 seconds.