Why is MS Office called a ”productivity suite”?

Rather often when I read posts or articles about software I see people referring to Microsoft Office as the ”productivity suite” and I can´t really understand why. Maybe it is because English is not my native language. Some may think this is another stab at Microsoft beacuse they are the evil force in software universe. I will do that in other posts 🙂 This is just about semantics and choice of words. If MS Office is called that means that it using them must increase or at least contribute to productivity. But all the other software I like image and video editing software or for that sake alternative text editiors don’t they also contribute to productivity. It seems like there is a category missing here. Or is it because they span such a wide areas of use that no single catagory seem to fit. Also, and this is a question, does the OpenOffice suite fall in the same ”productivity suite”-category for these authors?