Half (or more) of Microsoft's business, and far more of their profit, is two product lines: Windows, and Office.
They're also synergystically linked: if you're running on Windows, you're far more likely to want/need Office, and if you're using Office, you're far more likely to want Windows.
Crack either side of that diptych, and you've vastly undermined the business. Apple is attacking both. The OS through both its laptop and desktop (yes, you can still buy desktop Macs) offerings, but increasingly, mobile (iPhone, iPad, even iPod). Apple iWork is a competitor to Office, and some products (notably Keynote) are vastly superior to the Microsoft offerings.
Apple's not the only competition, of course. Google appear primed to take on more of the space as well (Google Apps, Android). And there's even Linux on the desktop. One of these years.
They're also synergystically linked: if you're running on Windows, you're far more likely to want/need Office, and if you're using Office, you're far more likely to want Windows.
Crack either side of that diptych, and you've vastly undermined the business. Apple is attacking both. The OS through both its laptop and desktop (yes, you can still buy desktop Macs) offerings, but increasingly, mobile (iPhone, iPad, even iPod). Apple iWork is a competitor to Office, and some products (notably Keynote) are vastly superior to the Microsoft offerings.
Apple's not the only competition, of course. Google appear primed to take on more of the space as well (Google Apps, Android). And there's even Linux on the desktop. One of these years.