Computer Science: 97 interactive topics
Algorithms, programming, data, networks, hardware and safe, responsible use of technology.
About Computer Science at secondary level
Computer Science on LearnViz SecondaryEdu has 97 interactive topics. Computing topics explain how software, hardware and data work, with diagrams and models that show each step in order.
Every topic has a clear definition, key points written for secondary school, an animation you can control, and a three-question quiz. Topics are independent, so you can start anywhere.
How to study Computer Science with LearnViz
- Start with a topic you already know a little about, then move to one that is new to you.
- Use the animation before you read the key points. Predicting the result first makes the explanation easier to remember.
- Finish each quiz, then review the questions you got wrong. Mark a topic complete once you can explain it in your own words.
- Trace one example by hand, writing down each value as it changes.
97 topics
1What Is a Computer?A computer is an electronic device that takes input, processes data…2Input and Output DevicesInput devices send data into a computer, while output devices…3The CPUThe central processing unit is the brain of the computer that…4The Fetch-Decode-Execute CycleThe fetch-decode-execute cycle is the repeated process in which the…5Memory: RAM and ROMRAM is temporary memory for running programs and ROM is permanent…6Secondary StorageSecondary storage keeps data permanently, using devices such as…7Operating SystemsAn operating system manages hardware and software, giving users an…8Application and System SoftwareApplication software helps users do tasks like writing or gaming,…9Binary NumbersComputers use the binary system of ones and zeros, because circuits…10Converting Binary and DecimalBinary is converted to decimal by adding the place values where…11HexadecimalHexadecimal is a base 16 system using digits 0 to 9 and letters A…12Binary ArithmeticBinary arithmetic follows the same rules as decimal, adding digits…13Text, Images and Sound as DataComputers store text, images and sound as binary numbers, using…14Units of DataData is measured in bits and bytes, with larger units such as…15CompressionCompression reduces file size so that files take less storage and…16Logic GatesLogic gates are the building blocks of digital circuits that take…17Truth TablesA truth table lists every possible input combination of a logic…18AlgorithmsAn algorithm is a precise sequence of steps for solving a problem…19FlowchartsA flowchart is a diagram that shows the steps of an algorithm using…20PseudocodePseudocode is a way of writing an algorithm in plain structured…21Decomposition and AbstractionDecomposition breaks a big problem into smaller parts, and…22Pattern RecognitionPattern recognition is spotting similarities between problems so…23Computational ThinkingComputational thinking is a way of solving problems using…24Variables and Data TypesA variable is a named location in memory that stores a value, and…25Operators and ExpressionsOperators perform calculations and comparisons on values, such as…26Selection: If StatementsSelection lets a program make decisions by running different code…27Iteration: LoopsIteration repeats a block of code, using loops such as for and while.28Arrays and ListsAn array or list stores a collection of items under one name, each…29Strings and String HandlingA string is a sequence of characters, and string handling includes…30Functions and ProceduresA function is a reusable block of code that performs a task and can…31Scope of VariablesThe scope of a variable is where in a program it can be used,…32Input and Output in ProgramsPrograms interact with users by reading input and displaying…33Validation and VerificationValidation checks that data is sensible and in the right format,…34Testing and DebuggingTesting finds errors in a program and debugging fixes them, using…35Types of Programming ErrorPrograms can have syntax errors, logic errors and runtime errors,…36Searching AlgorithmsSearching algorithms find an item in a list, using linear search or…37Sorting AlgorithmsSorting algorithms arrange data in order, such as bubble sort,…38Efficiency and Big OEfficiency describes how the running time or memory of an algorithm…39RecursionRecursion is when a function calls itself to solve a smaller…40Programming ParadigmsProgramming paradigms are styles of programming, such as…41Object-Oriented ProgrammingObject-oriented programming organises code into objects that…42Programming LanguagesProgramming languages are formal languages used to write…43Compilers and InterpretersA compiler translates a whole program into machine code before it…44Introduction to PythonPython is a popular high-level language known for readable code,…45Introduction to HTMLHTML is the markup language that defines the structure and content…46Introduction to CSSCSS describes how HTML elements are styled, controlling colour,…47Introduction to JavaScriptJavaScript is a programming language that makes web pages…48Web Browsers and Web ServersA web browser requests pages from web servers, which send back…49How the Internet WorksThe internet is a global network of networks that sends data as…50Networks: LAN and WANA LAN connects devices in a small area such as a school, while a…51Network TopologiesNetwork topology is the layout of a network, with common types…52Protocols and TCP/IPNetwork protocols are rules that let devices communicate, with…53IP Addresses and DNSAn IP address is a unique number identifying a device on a network,…54Packet SwitchingPacket switching breaks data into small packets that travel…55Wireless and Mobile NetworksWireless networks send data using radio waves, including Wi-Fi,…56Cloud ComputingCloud computing means using remote servers on the internet to store…57Cyber Security ThreatsCyber security threats include malware, phishing, hacking and…58Protecting Data and PasswordsStrong passwords, encryption and updates protect data from…59EncryptionEncryption scrambles data using a key so that only authorised…60Firewalls and AntivirusA firewall controls network traffic, and antivirus software detects…61Online SafetyStaying safe online means protecting personal information, being…62Digital FootprintA digital footprint is the trail of data you leave online, which…63Cyberbullying and Respect OnlineCyberbullying is using technology to hurt or embarrass others, and…64Copyright and LicensingCopyright law protects the creators of original work, and licences…65Data Protection and PrivacyData protection laws set rules for how organisations collect, store…66Ethics of TechnologyTechnology raises ethical questions about privacy, fairness, jobs…67Artificial IntelligenceArtificial intelligence is the ability of computers to perform…68Machine LearningMachine learning is when computers improve at a task by finding…69RoboticsRobotics is the design and use of machines that can carry out tasks…70DatabasesA database is an organised collection of data that can be searched,…71SQL BasicsSQL is a language for managing and querying data in relational…72SpreadsheetsA spreadsheet organises data in cells arranged in rows and columns…73Data Representation of ImagesA digital image is made of tiny coloured squares called pixels, and…74Digital SoundDigital sound is made by measuring a sound wave at regular…75Embedded Systems and IoTEmbedded systems are small computers built into devices, and the…76Computer HistoryComputers have evolved from mechanical calculators to room-sized…77Alan Turing and Ada LovelaceAda Lovelace wrote the first algorithm for a machine, and Alan…78Moore's LawMoore's law is the observation that the number of transistors on a…79Graphics and AnimationComputer graphics create images using shapes and pixels, and…80Game DesignGame design involves planning rules, goals, characters and levels,…81Project Management and TeamworkComputing projects are planned in stages, with teams sharing tasks…82User Interface DesignA good user interface is clear, consistent and easy to use, helping…83Accessibility in TechnologyAccessible technology is designed so that everyone, including…84Careers in ComputingComputing offers careers such as software developer, network…85Green ComputingGreen computing aims to reduce the environmental impact of…86Search Engines and Information LiteracySearch engines index the web and rank pages, and information…87Email and Online CommunicationEmail, messaging and video calls let people communicate instantly,…88Blockchain and CryptocurrencyA blockchain is a shared digital ledger of linked blocks of records…89Virtual and Augmented RealityVirtual reality creates a fully digital world, while augmented…90Big DataBig data refers to enormous, fast-growing collections of…91Quantum Computing BasicsQuantum computers use qubits that can be in several states at once,…92Pixels and Screen ResolutionA pixel is the smallest dot of colour on a screen, and resolution…93Version Control and CollaborationVersion control tracks changes to files over time so teams can work…94APIs and Web ServicesAn API is a set of rules that lets one program ask another for data…95Mobile Apps and DesignMobile apps are programs designed for phones and tablets, built to…96Cookies and Online TrackingCookies are small files that websites store in your browser to…97Data Structures: Stacks and QueuesA stack is a last-in first-out list and a queue is a first-in…
Computer Science: frequently asked questions
How many topics are in Computer Science?
Computer Science has 97 interactive topics on this site. Each one has its own page, so you can study them in any order.
Is Computer Science free to use?
Yes. Every topic, animation and quiz can be used in your browser without creating an account. Your progress is saved only on your own device.
Who is the Computer Science content for?
It is written for secondary school students studying Computer Science, and for teachers or parents who want a clear visual explanation. It supports your syllabus and your teacher rather than replacing them.
How do I move between topics?
Each topic page has Previous and Next links, a list of related topics, and a search box in the header. You can also filter the list on this page to find a topic by name.