The Basic Parts Of A Computer & How To Upgrade Them [Technology Explained]

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diagram of the basic parts of a computerDo you know how to use a computer? Of course you do. But how familiar are you with what’s inside that shiny metal box of yours? For as complicated as the inner workings of computers may seem, they are really only made up of a few key pieces. If you ever have a hardware problem or would simply like to upgrade one of those pieces, it helps to know what they do and where they are located.

Today we’re taking it back to the basics. In this article, I am going to name the basic parts of a computer, describe what they do, show you where they are usually located, and give you a few tips on how to upgrade them. So the next time your hard drive dies or your CD-Rom stops reading discs, you don’t have to pay for a house call from your neighborhood PC-repair man.

[Note]: This article is meant to be a basic diagram of the basic parts of a computer and is by no means a complete and accurate description of everything that is inside a computer. While replacing computer parts, there are various things to consider that I will not be able to cover here, like compatibility issues.

This article is not about how to build a computer. For that, I invite you to check out our guides, How to Build a Gaming PC and The Idiot’s Ultimate Guide to Building Your Own PC. You can find a lot of what will be here in our Basic Computer Terms You Should Know Before Buying A PC article.

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Now that most of the professionals and hardcore geeks have left, onto the basics!

diagram of the basic parts of a computer


Your motherboard is where all of the components I’m going to talk about will inevitably plug into. It has slots for most removable components like RAM, IDE/SATA drives, and video cards. If you are a beginner, I wouldn’t advise you to upgrade your motherboard yourself, but a lot of the other components I will cover require you to unplug things from the motherboard.

To view system specs, try Speccy.

Central Processing Unit (CPU)

See: What Is A CPU and What Does It Do? [Technology Explained]

If a computer was a human, the CPU would be the brain. It is the single most important piece of a computer because it does all the processing of data, calculations, and it controls most of the other components. The CPU is usually located directly underneath a cooling unit on the motherboard.

Once again, I would not advise you to upgrade your CPU yourself if you are a beginner. In most cases, upgrading your CPU will require a new motherboard, along with a heat sink and perhaps other components. While I won’t go into it here, you can find a very informative and detailed walk-through on How to Upgrade a Processor here.

Power Supply Unit (PSU)

name the parts of a computer

The PSU provides power to your whole PC and is usually located in the top-back of your computer. PSUs are rated by the amount of power they give out (e.g. 600 watts). It is important that your computer is powered properly so that it does not fail on you.

To upgrade your PSU, you should research the specifications of the other components in your system, most importantly the video card and CPU. You also want to make sure you get the proper connectors for your system.

Calculate your PC power supply with eXtreme PSU Engine.

Hard Drive

name the parts of a computer

Your hard drive is what stores all your data long-term. Hard drives are generally kept in the bottom-front of most PCs, and are usually connected to the motherboard via SATA cables (IDE for older PCs). Also, there will be a power cable.

If yours dies on you or you simply want to upgrade to a bigger one (storage wise), you just need to purchase one with the proper connections. Hard drives are usually screwed into place.

Random Access Memory (RAM)

name the parts of a computer

RAM is temporary (or short-term) memory and helps out with overall system performance and speed. RAM consists of long sticks that are plugged directly into your motherboard. Consult your owner’s manual or system information to determine the maximum amount of RAM that’s supported by your system.

Upgrading RAM depends on how many slots you have and the maximum size each slot supports. Some computers require that you have the same amount of RAM in each slot. This would be listed in your manual as well.

Disk Drive (CD-ROM or DVD-ROM)

parts of a computer system

Your disk drive(s) is/are generally located at the top-front of your machine. They allow you to play and burn (copy) CDs and DVDs. Since discs spin in these drives, they occasionally break on you. Also, the speed at which these drives can read and write data is constantly increasing.

To upgrade a CD or DVD-ROM, simply unplug and unscrew the existing drive and plug the cables (power, SATA/IDE) into the new drive. If you are upgrading from one drive to multiple drives, you can learn about setting the drives to master/slave configuration here.

Video Card

diagram of the basic parts of a computer

Your video card is what allows you to view anything on your monitor (makes sense). If you’re into gaming, you either left already to learn how to build a gaming PC or you stuck around to see what I had to say about video cards.

Modern games require better video cards. Your video card is usually located in the bottom-back portion of your computer case. Aside from size specifications, slot placement, motherboard type, processor speed, and power intake – which are all compatibility issues – upgrading your video card is as simple as unplugging the stock card and plugging the new video card in its place.

How did I do? Leave a comment below and please be gentle!

Image Credit: William Hook, BBC News, William Hook,, mattk1979, Renee V, mattjb

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11 Comments - Write a Comment



Thanks for article! And I hear the word “GPU” alot, what does it means and does it defer from a graphics card?


The Graphics Processing Unit (GPU) is a specific component of the graphics card.


Thanks and is there any reason to get a sound card if one comes with your motherboard?


For 99% of people, no. Most onboard sound is fine for general use. You’d probably only need one if you’re working with audio equipment.



Very informative article for sure. I may have to add you to the technology or DIY section of



This what I am lookin for .


Prateek Jain

gud article



Great article, Steven! Maybe include something about how you need a separate GPU in order to upgrade it. I think if your GPU in “integrated” then you cannot upgrade it. I could be wrong.


campy kattil

hahahahaahahaha thanks im koleen jinomian…………..



Correct, you can’t upgrade the integrated/on-board graphics, but you can add a separate graphics card (as shown in the article) which will takeover from the on-board graphics.


Steve Campbell

Thanks guys! I’m glad you liked the article. And thanks Chris for answering the questions for me. I always appreciate the participation of the MUO community!

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