Computers are magic. Have you ever wondered what’s inside your computer? Is there a little wizard inside your computer? Sadly, the answer is no, but what’s actually inside your computer is still even more interesting! Read more to find out!

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Discover the parts of a computer

Today, we'll guide you through what's inside your computer! We'll start with the important hard drive, and go all the way through the screen.

1. Hard Drive

Have you ever received a “disk space full” error message? After receiving this message, you’re forced to delete files from your computer for the error to go away. What’s the “disk” this message is referring to? The hard drive (sometimes called hard disk) is where most of the information on your computer is stored. All your programs, images, movies, games, documents, and your operating system are stored here.

Most hard drives nowadays are between 60 GB to 1 TB in size and are meant to store a lot of data. Computers not created within the past 5 years or so may use an actual disk where the data is stored by writing microscopic dots on an actual rotating disk. Newer computers have what’s called “solid state drives” (SSDs) that do not use an actual disk.

2. RAM

You may have also heard of “memory” for a computer whose number is much smaller than 60 GB, maybe something like 8 or 16 GB. This memory is referred to as RAM, or “random access memory.” The problem with hard drives is they are really slow. RAM stores less memory but the computer is able to access the data faster.

Think of this analogy: imagine a shoe store. The hard drive is like the storage at the back of the store that has all the shoes in all the different sizes and colors. RAM is like the storefront that presents a couple shoes. When you go to the shoe store, it’s easy to find if they have the style or brand of shoe you’re looking for but it takes more time to find your actual color or size.

3. Processor

So the hard drive and RAM store information but what part of the computer actually does the computing? This is called the processor or CPU. The processor contains billions of microscopic circuits that switch on and off. Processor speeds are usually measured nowadays in gigahertz (GHz). One GHz represents 1 billion processor cycles in one second. Processors nowadays usually have multiple “cores.” One core represents a processor. So a dual core processor is a processor that actually contains two processors inside of it but operates as one!

4. Graphics Card

Some specialized computers, especially computers meant for gaming, have a separate processor for generating visual graphics. These processors are graphics cards, also called GPUs (graphical processing units). These cards not only contain a separate processor, but also separate RAM too. Graphics cards are measured in both gigahertz for the processor speed and gigabytes for the RAM size.

5. Power Supply

Without electricity to power these parts, your computer would be pointless! The power supply is the source of electricity for the computer. In laptops it’s a battery and on desktop computers it’s plugging into a wall.

6. Fan / Cooling System

Have you ever felt your laptop get hot? Or have you heard your computer making a soft blowing noise? Computers get hot because these parts have electricity flowing through them. Computers especially get hot for intense programs like games. To prevent these components from melting (yes this can happen!), computers have fans to help keep the parts at a reasonable temperature. Some really fancy computers even have liquid cooling systems!

7. Motherboard

The motherboard is what connects all these parts together. For components inside of the computer, the motherboard is a large piece of silicon that has paths for electricity to flow between the different components. The motherboard also connects to external ports, like USB or HDMI.

8. Peripherals and Screen

What can you connect to these external ports? For starters, you can connect a screen such that you can see the programs on your computer. You can also connect a mouse/trackpad and keyboard such that you can interact with these programs. In a laptop, the screen, keyboard, and trackpad are directly connected to the motherboard without wires. In addition to these, one can connect to other devices such as external hard drives, your phone or camera, etc.

Now you know the parts of a computer

What’s inside a computer isn’t quite magic, but it comes close! Want to learn more about how computers work? For younger students Create & Learn’s Micro:Bit class is a great introduction to circuit programming in a simulator. For intermediate students, Create & Learn’s Smart Devices class introduces students to the world of Arduino circuit programming.

Written by Brandon Lim, a Create & Learn instructor and curriculum developer. Brandon also works full-time as a software engineer and holds a BS in Computer Science from Johns Hopkins University. Brandon has experience teaching coding to students of all ages from elementary school to college and is excited to share his deep knowledge and relentless passion for coding with the next generation of technology leaders.