This is the second article in the series on “Computer Basics”. In this article I talk about the major components that make up a computer – the hardware. This information gives you a basic idea of how a computer works and is a must for anyone who wants to upgrade or repair their computer, or just wants to have a basic understanding of how a computer works.

Part one – computer devices and how they interact with the computer
Part three (Coming soon) – basics of computer software

Case

What and where? The case is a metallic box that encloses the internal components of a computer.

What does it do? The case is like the skeleton of the computer. On the outside it encloses and protects the computer; on the inside it holds the internal components in place. If you look inside the case, you’ll see lots of slots and holding places where you can secure the different components.

Power Supply

What and where? The power supply is the box that has lots of wires coming out of it. It’s usually located in the upper-back corner of the computer case.

What does it do? The power supply provides electricity to the internal components of the computer. Each component needs specific type of electricity to work correctly. The power supply converts standard electricity that comes from the wall to specific electricity that each of the components can use.

Motherboard

What and where? The motherboard is the biggest circuit board in the computer. It’s usually attached to one wall of the case, taking up most of that wall.

What does it do?

The motherboard does the following:

1. Primarily, it connects all the internal components together, giving them the circuitry to communicate with each other.
2. It has slots that provide the computer with extended functionality. The motherboard has slots where you can add all sorts of device cards – video cards, wireless network cards, network cards, etc.
3. It has some integrated devices in it. Back in the day you’d have to have a sound card for audio, a network card to connect to the internet, a modem card to connect to a telephone line, and so on. Since these cards became so common, they started putting them into the motherboard itself. Now, most motherboards come with integrated sound, network, modem, and sometimes video card devices. These are called integrated devices – devices integrated into the motherboard.

CPU/Processor

Terminology The CPU (Core Processing Unit) is also called the “processor”.

What and where? The CPU is a chip that is directly attached to the motherboard. It’s usually hidden under a heat sink (metal thing with fins) and a fan, so it’s not directly visible.

What does it do? The CPU carries out all the logic for the computer. It decides on everything that goes on in the computer and does all the calculations.

Main Memory

Terminology: Also referred to as physical memory, memory, or RAM.

What and where? Main memory is either one or multiple thin circuit board strips, with chips and possibly heat sinks plastered on both sides. These strips plug into the motherboard.

What does it do? Like the human brain, a computer has a short-term and a long-term memory. Short-term memory is made for speed and long-term memory is made for storage. Because short-term memory is mostly concerned with speed, space in it is more expensive than space in long-term memory. That’s why a computer has a smaller amount of short-term memory for things that the computer needs to access quickly, and lots of long-term memory for things that need to be stored for later.

Main memory is the short-term memory. Whenever the processor needs to access some data, it loads it up into main memory and works with it there. For example, when you install a video game, you put a bunch of data (music, videos, pictures, saved games, etc.) on the hard drive (long-term memory). And it remains on the hard drive whether your computer is on or off. Then when you load up the game to play it, your computer puts lots of that data into short-term memory – so that the processor can access it quickly while you’re playing.

It’s important to understand that main memory is what’s called “volatile memory”, meaning that it can store information only while it’s receiving power. When you start your computer, data is loaded from storage into main memory so that the processor can work with it. When you turn off your computer the main memory gets cleared out.

Hard Drive

Terminology: Short for ‘hard disk drive’.

What and where? A little enclosed box that sits below the CD/DVD drive and the floppy disk (if there is one) in the case, close to the power button.

What does it do? Please read the information on short-term vs long-term memory, in the main memory section. The hard drive is the long-term memory (storage memory). It’s also non-volatile memory, meaning that it doesn’t need power to retain data; you can take a hard drive out of a computer and it will still have all the data on it just like before.

Video Card

Some applications are too graphically intensive for an integrated video card to handle and have to be handled by a more powerful standalone card. For that reason, standalone video cards are pretty common – and that’s why I’m including a section about them.

What and where? The video card is a circuit board that plugs into the motherboard – with input/output ports sticking out of the back of the case. Powerful video cards are really big circuit boards (usually second largest after the motherboard) that have heat sinks and a fan or two; sometimes they are enclosed within a case of their own.

What does it do?

The video card mainly does two things:

1. It tells the monitor what images to display
2. It does 2D and 3D calculations

Modern video cards are pretty powerful devices, often mimicking a computer inside of the actual computer. Video cards have their own processor (GPU) and their own memory. The computer CPU offloads all graphics related calculations to the video card, which is specifically optimized towards graphics calculations. Some applications, like 3D video games, are very graphically intensive and can fully utilize a very powerful video card.

CD/DVD Drive

What and where? A CD/DVD drive is a box looking device located in the upper front of the computer case. It has a slide out tray to put the CDs/DVDs into.

What does it do? A CD/DVD drive reads and sometimes writes CDs and DVDs. In order for a CD/DVD drive to be able to write CDs and DVDs, it also has to be a CD/DVD burner.

Conclusion

That pretty much covers the high level overview of computer hardware. Please continue to part3(Coming soon) of the “computer basics” tutorials – software basics.

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Some of the images on this page were taken from freephotosbank.com