*sigh*
It's annoying when ignorant journalists take it upon themselves to define terms they don't understand.
The "tower" is the computer. It's not the "central processing unit", or CPU. The CPU is the microchip that processes information and controls the computer; it lives in the "tower" on the motherboard or mainboard. There may be more than one of them in a single computer.
For those who are not computer-savvy, not even computer-literate, please always remember:
CPU(central processing unit) != tower