Computer Science & IT

How computers, the internet, operating systems, databases and data structures actually work — the core knowledge under every tech career.

7 free lessons · 4 hands-on labs · 1 practice quiz · 100% free

Start lesson 1 — How a Computer Works Take the CS & IT quiz

What you will be able to do

Explain CPU, RAM, storage and operating systems
Describe how the internet delivers a webpage
Work confidently with binary and data
Design simple databases and run SQL queries

Step 1 · Learn

Your lessons, in the right order

Read them in this order — each lesson builds on the one before it. Every lesson is free and opens on its own page.

1 How a Computer Works: CPU, RAM and Storage ExplainedCPU, RAM and storage are the three parts behind everything your computer does. A kitchen analogy makes each part obvious — and helps you buy or fix computers with confidence. Beginner11 min read 2 How the Internet Works: From Browser to WebsiteYou type an address and a page appears in two seconds. What actually happens in between? DNS, servers and HTTP explained in plain, simple words. Beginner10 min read 3 Binary and Data: Why Computers Use 0 and 1Computers speak in only two symbols: 0 and 1. It sounds too simple to power the modern world — until you see how counting, text, photos and music all become binary. Beginner10 min read 4 Operating Systems ExplainedWindows, Linux, Android — the operating system is the manager of your whole computer. What an OS actually does: processes, memory, files, users and security, explained with a hotel-manager analogy. Beginner10 min read 5 Data Structures Basics: Arrays, Lists and StacksPrograms are algorithms plus data structures — how you organise data decides how fast everything else becomes. Arrays, lists, stacks and queues explained with everyday pictures and Python examples. Beginner11 min read 6 Cloud Computing: What It Is and Why It MattersThe cloud is not a place in the sky — it is other people’s powerful computers, rented by the hour over the internet. IaaS, PaaS, SaaS, and why every career path now touches the cloud. Beginner10 min read 7 Databases Explained: Tables, Keys and SQL for BeginnersEvery app you use \u2014 from WhatsApp to your university portal \u2014 stores its data in a database. Learn tables, rows, primary and foreign keys, relationships, and your first SQL queries, in plain words. Beginner11 min read

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Step 2 · Practice

Hands-on labs for this track

Reading is not enough — do each lab yourself. Labs run Easy → Intermediate → Tough.

4 Lab 4 · Binary, Decimal and Hex Conversion LabConvert numbers between binary, decimal and hexadecimal by hand and verify with a calculator, including an ASCII letter and a colour code. 🟢 Easy · Beginner50 min 6 Lab 6 · Computer Hardware Identification and OS Settings LabIdentify every major component of your own device from its real specifications, then audit key OS settings: updates, storage, startup apps and permissions. 🟢 Easy · Beginner60 min 9 Lab 9 · SQL Database Lab: Create Tables and Run QueriesDesign a small student database, create tables with keys, insert real-shaped data, and answer business questions with SELECT, WHERE, JOIN and GROUP BY. 🟡 Intermediate90 min 22 Lab 22 · Systems and Data Lab: Data Structures in a Real Scenario (CS Tough)Choose the right data structure for four real scenarios, implement each in Python, and prove your choice with timing and a written justification. 🔴 Tough · Advanced2-3 hrs

Step 3 · Test yourself

Finished the lessons and labs? Take the CS & IT practice quiz and check your score instantly — then revise whatever you missed.

Start the quiz

See the full learning path

The CS & IT learning path lays out lessons, labs and the quiz as one guided journey, beginner to advanced.

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