Welcome back! Today we’re continuing our two-part series on computers – perhaps the most important innovation in human history!

(Yes, that’s a big claim… and surely, the wheel and sliced bread would argue otherwise… but since computers are the basis for so many other innovations, we think they deserve the top spot!)

Last week, we learned about two fundamental computing concepts: input/output (the basic function of computers) and binary (the language of computers).

Today, we’ll bring it all together by learning about software, hardware, and the key components inside a computer.

Note: We’ll briefly summarize the main concepts from Part 1 in today’s article, so you don’t need to read it before reading this article – unless you’re curious, of course!

First, a quick refresher on Input/Output and Binary

Image source: Computer Hope


Last time, we learned that a computer is an “input/output device”.

That means pretty much any device that can receive an input, then produce an output, can be considered a computer.

The most basic example – and not coincidentally, the first kind of computer – is a calculator. When you input “1+1”, it gives you the output: “2”. There’s a lot more going on under the hood, of course, but for now this is all you need to know.

We also learned that computers “speak” a language called binary – the language of computers!

Binary is essentially a way to represent (and communicate) data using only 1s and 0s. Each “1” or “0” in binary actually represents an electrical signal – which you can think of like an on/off switch. For example, when one computer wants to communicate the number “5” to another, it will send 3 signals: first an “on” signal, then an “off” signal, then an “on” signal again – which the other computer will interpret as “101”.

So! Now you know that a computer receives “inputs” and gives back “outputs”. You also know it does this using a series of 1s and 0s, or on/off signals, called “binary”. This simple system is the basis for all sorts of complex tasks!

Now, to see how it all works in practice, let’s look inside a computer!

What’s inside a computer?

When we talk about computers, we’re usually talking about two things that work together harmoniously: software and hardware.

As you probably know, the hardware is the computer itself, while the software is all the programs you run on it – like your web browser, games, calculator, etc.

These are two very different things, but they rely on each other. So to answer the question, we need to look into both!

Alright then… what is hardware?!

Image source: Tes Teach


In an actual computer, you have a number of components that all work together. All of this stuff is called “hardware”. Most computers have 7 essential hardware components:

  • Computer case or tower: This is what holds your computer together (and protects the delicate electronics inside).
  • Central Processing Unit (CPU): This “master chip” controls all other parts of the computer. Since it needs to do a bunch of different things, it has many smaller parts inside, called “circuits”. Some circuits do simple math and logic while others send and receive information. It delegates tasks and basically runs the whole show.
  • Power Supply Unit (PSU): This is how your computer gets the electricity it needs to send all those signals. In many cases, it’s a battery instead of a plug.
  • Random Access Memory (RAM): Your RAM determines how quickly your computer is able to multitask. With more RAM, your computer goes faster – especially when switching between programs.
  • Hard Drive (HDD): This essential component stores your data for later access. It uses binary to do this – each saved file you have is actually a long binary number, stored using a spinning disc with magnetic coatings and heads that “write” the numbers for later access.
  • Graphic Processing Unit (GPU): This is responsible for graphics – the visuals on your computer. The more powerful this unit is, the more vivid and smooth your videos, editing programs and video games will appear.
  • Motherboard: All these components can’t just be floating around, right? That’s where the Motherboard comes in – it acts as a platform for most of the other computer parts. It also has connectors to plug in other components. (For example, if your computer only has 1 USB port, you can blame the Motherboard!)

All of these components work together to allow different software (or programs) to run. For example, video games need a powerful GPU to display colorful, fast-moving graphics, while computers that do a lot of multi-tasking need a fast CPU and RAM.

Got it! Now, what’s software?

Image source: Extraupdate


You’ll need most, if not all of these components to run today’s powerful software – which is what you actually see and use on the computer.

Software may run smoothly to you, but it’s working hard in the background. Every little action is like flipping thousands of switches! For example, let’s say you’re downloading a file. This requires your CPU to tell your GPU to display the mouse cursor moving toward the file. It also requires your RAM to help “remind” your computer what it’s doing… and your hard drive needs to supply the data requested.

It’s a lot of work… and that means flipping a lot of switches (or, actually, sending electrical pulses – but that’s a story for another article).

This image shows binary being transmitted via electrical pulses. Image source: Khan Academy


The number of switches you have and the speed at which you can flip them depends on your hardware. This is represented in “bits” – each bit represents a switch. It gets a bit more complicated, but the idea is essentially: the better your hardware, the more your software can do. 

This also means software is limited by hardware. That’s why we need to keep buying new computers – as we become capable of creating better hardware, we have more “switches” available to create better software with.

And as software creators make requests, they push innovation in hardware… and so on and so forth. It’s the “cycle of innovation” at work!

Conclusion: Computers are complicated, but it all comes down to 1s and 0s!

So there you have it! That’s a verrrrrry basic overview of how computers work.

We hope you enjoyed this 2-part series. We had a lot of fun researching it. Computers are incredibly exciting – they give us access to so many different innovations. While there’s a lot more to cover than what we’ve learned today, this is a good start in understanding these fascinating machines!

Do you have a question about a modern innovation like computers, Artificial Intelligence or Bluetooth? Let us know in the comments below!

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