Apple is four companies in one

Why Competing with Apple Is So Difficult, article. 

...But competing with Apple is difficult because Apple, Inc. is actually four diverse and thriving companies all wrapped up into one. It's a hardware company, a software company, a services company, and a retail company. Most technology companies in the world can manage one or two of these disciplines, but only Apple has all four entities working in harmony.

What a thought! When you think about it, making a very good, not to mention big, company in any of these four categories is a herculean task. Making all four is a sensation and unique. And to make all four and make them work all in concert as one, is a historic accomplishment. This is not an overstatement. Sony, for instance, has suffered huge setbacks because some arms of the company did not know what other arms were doing, and those arm were nowhere as big and different as the ones Apple are wielding like the four mechanical arms of Doc Octopus.