a. Noun
A computer's Central Processing Unit (CPU); considered the
brain of the computer, it is a small
chip that sits in a special socket on the motherboard and processes instructions and calculations that allow the computer to function, then feeds them to the other components.
High-end CPUs are often used alongside
high-end GPUs by enthusiast PC users to
run demanding programs more efficiently.
The clock speed, or performance, of the CPU is measured in
clock cycles per second, or Gigahertz (GHz) and Megahertz (MHz), and can be overclocked to give it a boost.
b. Noun
An innocent piece of computer hardware that was swarmed by nerds who project their feelings of inadequacy and lack of purpose onto it and its manufacturers who ultimately don't care about any of them.
Unsuspecting Normal Person:
Hi, I'm planning on building a gaming PC and I want to choose the CPU first. Does anyone have any recommendations?
Intel Fanboy:
YOU MUST BUY INTEL.
AMD Fanboy:
FUCK THAT
GUY, YOU MUST BUY
AMD.
(a 15-page flame war between the fanboys ensues, both sides leave enraged with the question unanswered)