CS Fundamentals Notes

Practice122 MCQs & 92 exam questions with answers & mark schemes →

A complete, self-contained CS Fundamentals course — free, and open to anyone, anywhere. 16 lessons published so far — each with notes, worked examples, a diagram you can move, flashcards and a quiz — and more are being written.

Also called Free online course, Self-study course.

01

How Computers Represent Data

▸Number SystemsWhy a machine that only knows two symbols can represent anything · 20 min · 8 questions→▸Text, Sound and ImagesHow a machine that stores only numbers holds a photograph · 20 min · 8 questions→

02

Logic and Circuits

▸Digital Systems and Logic DesignGates, truth tables, and building arithmetic out of switches · 20 min · 8 questions→▸Boolean Algebra and Logic CircuitsSimplifying a circuit on paper before building it in silicon · 24 min · 8 questions→

03

Inside the Machine

▸Introduction to SystemsWhat is actually inside the box, and how it runs a program · 20 min · 8 questions→▸CPU Architecture and Parallel ProcessingWhat is inside the processor, and why one instruction takes several steps · 26 min · 8 questions→▸Operating Systems: Structure and ServicesThe program that makes every other program possible · 20 min · 8 questions→

04

Thinking Computationally

▸Computational ThinkingBreaking a problem down until every piece is something you can actually do · 20 min · 8 questions→▸Algorithms & Big-OSorting, searching, and measuring cost honestly · 22 min · 6 questions→

05

Organising Data

▸Data StructuresArrays, lists, stacks, queues, trees · 24 min · 6 questions→

06

Ideas Behind Programming

▸Programming Paradigms and Exception HandlingFour ways of describing a computation, and what to do when it goes wrong · 24 min · 8 questions→▸RecursionA routine that calls itself, and the stack that makes it possible · 22 min · 8 questions→

07

Networks and the Internet

▸Computer NetworksHow a message crosses the world in fragments and arrives whole · 22 min · 6 questions→▸The Internet and the World Wide WebTwo different things, and what actually happens when you type an address · 18 min · 8 questions→

08

Artificial Intelligence

▸Introduction to Artificial Intelligence and Machine LearningWhat it means for a program to learn from data instead of being told the rules · 20 min · 8 questions→▸Applications of Artificial IntelligenceWhere AI is genuinely used, what it is worth, and what it costs · 18 min · 8 questions→

Frequently asked questions

What does CS Fundamentals cover?

All 8 chapters — How Computers Represent Data, Logic and Circuits, Inside the Machine, and more. The finished lessons carry notes, worked examples, an interactive diagram and a quiz; the remaining topics are mapped and being written.

Are there practice questions or past-paper-style questions?

Yes — 122 multiple-choice questions and 92 exam-style questions with mark schemes, all with answers, on the CS Fundamentals practice page.

Are the CS Fundamentals notes free?

Yes — completely free, with no sign-up or login. Every topic has notes, worked examples, an interactive diagram you can change, flashcards and a quiz that explains each answer.