Y7 Computer Systems - Lesson 3 : CPU, RAM and Storage

PART 1: A High-Tech Kitchen

Imagine your computer is a high-tech kitchen. To get anything done, like making a digital sandwich or playing a game, you need three key things: a chef, a countertop, and a refrigerator. These are the CPU, RAM, and Storage!

For a computer system to be able to store a lot of our files, pictures and videos, games that we play, applications that we use, etc, a big enough storage is important and necessary.

Today, most our devices, whether a smartphone, a tablet, a Chromebook or laptop, or our game consoles like Xbox or Sony PlayStation, have at least 128 GB of storage.

This is the newest Xbox in the market with 1 Terabyte of storage to store all the games you can play!

And this one is a PS5 Pro with 2 Terabytes of SSD storage.

Look at the at the latest smartphone released by Samsung:

Pay attention to the size of the storage and the price of the smartphone.

1.2 The RAM (The Kitchen Counter)

Next, we have the kitchen counter. This is your computer's RAM (Random Access Memory).

• What it is: RAM is the computer's super-fast, temporary workspace. When you want to use a program or open a file, the computer puts a copy of it in the RAM to work on it.

• The Kitchen Analogy: You don't make a sandwich inside the fridge, right? You take your ingredients (data) out of the fridge (Storage) and put them on your counter (RAM). The counter is where the action happens because it's right there and easy to access. Also, when you have everything on the counter, it is way faster to make and cook. One you've cooked the food or made the sandwich, you put everything back in the fridge and clear out and clean the counter, right?

While working, the baker has everything he needs out of the fridge and pantry and on the counter. Once he is finished with the cake, he puts everything back where they belong and cleans the counter. The ready cake can now be stored in the fridge.

This is exactly how the computer works with storage and RAM. RAM is the counter.

• Key Facts about RAM:

  • It's very fast! Much faster than storage.

  • It's temporary. When you turn the computer off, the counter is wiped clean. Anything you didn't save is gone forever!

  • CPU has direct access to RAM.

  • More RAM is like having a bigger counter. A small counter gets cluttered if you try to do too many things at once, which slows you down. A big counter lets you have lots of apps and tabs open smoothly.

In short: RAM is short-term memory. It's fast, temporary, and your active workspace.

1.3 The CPU (The Chef)

Finally, the most important part: the chef! This is the CPU (Central Processing Unit).

You see? It is the chef who reads from the instructions of a dish from cooking book, weighs all the ingredients, does all the chopping, grating, grinding, mixing, etc, in the correct order, to make a delicious wonderful dish!

For each dish or cake, there is a set of step-by-step instructions(called algorithms in computers) that must be done in the right order to get the proper and desired product.

All computers, follow algorithms for every single task we set them to do. These algorithms are given to the computer systems using code. Programmers use different programming language to give instructions to computer systems, so that they can perform the tasks for us.

CPU and its functions:

• What it is: The CPU is the brain of the computer. It does all the thinking, calculating, and decision-making. It follows the instructions from your programs to make everything happen.

• The Kitchen Analogy: The CPU is your master chef. The chef takes the ingredients from the counter (RAM), follows the recipe (the program code), and does all the actual work—chopping, mixing, and cooking. The chef is the one who makes things happen!

• Key Facts about the CPU:

  • It's incredibly fast, performing billions of actions per second.

  • A faster CPU is like a faster chef who can prepare your meal (run your program) in less time.

• In short: The CPU is the brain. It does all the work.