What is a CPU? Definition of Central Processing Unit

The CPU (The Central Processing Unit) as the name suggests is the big daddy of all the parts on the motherboard and is the largest and the most expensive Integrated circuit within your computer. The CPU processes and exchanges all information and data with the other components within the computer.

Millions of transistors are crammed into an unbelievably cramped space of less than a square inch that makes up a chip, and it is chips like these that make up the CPU.

The CPU is mounted on the motherboard using a special socket which is permanently attached to the motherboard, complete with a lever mechanism to hold it in place (computers are moved about, jostled and thrown around these days). Additionally, this is done to secure a special connection to the power supply to each of the pins at the bottom of the integrated chip.

The working of the CPU will be dealt with in detail later (because it is too complicated to fit in with just an introduction to the CPU). However, you would be well off to know that the CPU does two things predominantly — process data and facilitate transfer between itself and the various other parts of the computer.

Intel and AMD happen to be riding the top of the CPU manufacturing order and they have been introducing special packages for CPU products. The way these packages and products come out, it is impossible to mount them on older, incompatible motherboards.

Every CPU manufactured and sold comes with a specification that includes Socket Type that defines the CPU’s package. Some of the commonly seen packages include Socket 370, Socket 478 and Socket 775. On the other hand, AMD packages include Socket 939, Socket 940 and Socket AM2. Newer sockets are continuously introduced as new CPU types are introduced.

The environs the CPU operates in is of special significance to proper working of the computers. As electrical energy is fed into the CPU and as the chip works away relentless at the breakneck speeds seen in processing powers of the computers today, a lot of heat is generated and has to be dissipated quickly. Metal or ceramic devices called heat sinks – sometimes aided by a cooling unit complete with a fan and boasting a rather large surface area do the job of conducting the heat away, off the top of the CPU quickly and efficiently.

All of this assembly is placed together (mostly to the right side of the motherboard, but might differ with some PC models). A typical CPU placement inside a mother board is as shown below.

CPU placed

This post is part of the series: Beginner’s Guide to Hardware

Not knowing about computers can make US obsolete. It is critical for us to develop an understanding of how these computers work since we have to make decisions about buying, repairing, selling, and using them. This continuing series is all about that and much more.
  1. An Introduction to Hardware for Beginners: A Primer
  2. An Introduction to Hardware for Beginners: Bits, Bytes and Beyond
  3. An Introduction to Hardware for Beginners: The Motherboard
  4. An Introduction to Hardware for Beginners: The Central Processing Unit
  5. An Introduction to Hardware for Beginners: The Chipset
  6. An Introduction to Hardware for Beginners: Understanding BIOS and Memory
  7. An Introduction to Hardware for Beginners: What Goes In and What Goes Out?