Know and understand software as programs for controlling the operation of a computer or processing of electronic data

1. Types and Components of Computer Systems

1.1 Hardware – definition & examples

Hardware comprises the physical parts of a computer that can be seen or touched. These components work together to process data, store information and provide input‑output (I/O) functions.

  • Central Processing Unit (CPU) – the “brain” that executes instructions and performs calculations.

  • Internal memory

    • Random‑Access Memory (RAM) – volatile memory for data that is being used by programmes.

    • Read‑Only Memory (ROM) – non‑volatile memory that stores firmware such as the BIOS/UEFI.

  • Graphics Card (GPU) – dedicated processor for rendering images, video and 3‑D graphics.

  • Sound Card – processes audio input and output.

  • Network Interface Card (NIC) – provides wired or wireless network connectivity.

  • Storage devices

    • Magnetic: Hard‑Disk Drive (HDD)

    • Solid‑state: Solid‑State Drive (SSD)

    • Optical: CD, DVD, Blu‑ray drives

    • Removable: USB flash drive, SD card

  • Input devices – keyboard, mouse, scanner, microphone, touch screen, graphics tablet.

  • Output devices – monitor, printer, speakers, projector, headphones.

  • Motherboard – main printed‑circuit board that interconnects all components and houses the chipset, slots and ports.

1.2 Software – definition & categories

Software is a collection of instructions, data and programmes that tell the hardware what to do and how to do it. Cambridge IGCSE 0417 splits software into two major categories:

  • System software – manages and controls hardware, provides a platform for other software, and includes utilities and firmware.

  • Application software – enables the user to perform specific tasks such as creating documents, communicating, or analysing data.

1.3 System Software

  • Operating System (OS) – core system software that controls all hardware resources, manages files, schedules processes and provides services to applications.

  • Device drivers – translate OS requests into signals that a particular hardware device can understand.

  • Utility programmes – perform maintenance, optimisation and security tasks (e.g., antivirus, disk defragmenter, backup tools, file‑compression utilities).

  • Firmware – low‑level software stored in non‑volatile memory; examples include BIOS/UEFI and firmware in routers, printers and embedded devices.

Operating‑system families, typical uses and pros/cons

OS familyTypical useAdvantagesDisadvantages
Desktop (e.g., Windows, macOS, Linux)General‑purpose computing, office work, gaming, multimediaWide software support; user‑friendly GUIs; strong hardware compatibilityCan be resource‑intensive; security vulnerabilities (especially Windows)
Mobile (e.g., Android, iOS)Smartphones, tablets, wearable devicesOptimised for touch, power‑efficient, integrated app ecosystemsLimited multitasking; tighter hardware constraints; app store restrictions
Server (e.g., Windows Server, Linux – Ubuntu Server, Red Hat Enterprise)Web, database, file and application hosting, cloud servicesRobust networking, high stability, multi‑user support, strong securityMore complex administration; often requires specialised knowledge

OS interfaces – advantages & disadvantages

Interface typeAdvantagesDisadvantages
Command‑Line Interface (CLI)Fast for experienced users; low resource usage; powerful scripting and automationSteep learning curve; no visual feedback; unsuitable for many novices
Graphical User Interface (GUI)Intuitive; easy to learn; supports multitasking with windows, icons and menusConsumes more CPU/RAM; may hide advanced options
Touch / Gesture‑based interfaceNatural interaction on tablets and smartphones; highly portableLimited precision; not ideal for complex text‑heavy tasks

1.4 Application Software – categories & examples

  • Productivity – word processors (Microsoft Word), spreadsheets (Excel), presentation software (PowerPoint), note‑taking apps.

  • Communication – email clients (Outlook), instant‑messaging (WhatsApp, Teams), video‑conferencing (Zoom, Google Meet).

  • Multimedia – image editors (Photoshop, GIMP), video players (VLC), audio editors (Audacity), video‑editing suites (Premiere Pro).

  • Educational – e‑learning platforms (Moodle), simulation tools (PhET), virtual‑lab software.

  • Business – accounting packages (Sage, QuickBooks), inventory management, ERP systems (SAP).

  • Control / Measurement – data‑acquisition software, SCADA, instrumentation programmes.

  • Applets & Small utilities – calculators, calendar widgets, browser plug‑ins.

  • Computer‑Aided Design (CAD) – AutoCAD, SketchUp.

  • Video‑editing & Production – Adobe Premiere, Final Cut Pro.

1.5 Main components of a computer system (syllabus mapping)

  • CPU – processes instructions, performs arithmetic/logic operations.

  • Internal memory

    • RAM – volatile, temporary storage while programmes run.

    • ROM – non‑volatile, stores firmware such as BIOS/UEFI.

  • Input & Output (I/O) devices

    • Input examples: keyboard, mouse, scanner, microphone, touch screen, graphics tablet.

    • Output examples: monitor, printer, speakers, projector, headphones.

  • Backing storage

    • Magnetic storage: HDDs, magnetic tapes.

    • Optical storage: CD, DVD, Blu‑ray.

    • Solid‑state storage: SSDs, USB flash drives, SD cards.

    • Distinguish internal (built‑in HDD/SSD) from external (USB, external HDD) devices.

1.6 Types of computers

Computers are grouped by size, portability and typical use. The syllabus recognises the following categories.

Computer typeTypical usesAdvantagesDisadvantages
DesktopOffice work, gaming, graphic design, video editingHigh performance; easy to upgrade; large displaysNot portable; requires external power
LaptopMobile work, study, travel, light multimediaPortable; integrated screen, keyboard and batteryLimited upgrade options; smaller screen than desktop
TabletReading, browsing, drawing, light productivityVery portable; touch interface; long battery lifeLimited processing power; on‑screen keyboard only
SmartphoneCommunication, apps, mobile internet, photographyHighest portability; always connectedSmall screen; constrained multitasking
PhabletMedia consumption, on‑the‑go productivityLarge screen in handheld form factorCan be bulky; still limited compared with laptops
Mobile computer (umbrella term)Encompasses laptops, tablets, smartphones and phabletsPortability and wireless connectivityGenerally lower expandability and processing power than desktops

1.7 Emerging technologies

  • Artificial Intelligence (AI) – powers smart assistants, predictive typing, image recognition and automated decision‑making.

  • Extended Reality (XR) – includes Virtual Reality (VR) and Augmented Reality (AR); used for immersive learning, design visualisation and entertainment.

  • Internet of Things (IoT) – connects everyday objects (e.g., smart thermostats, wearables) to the internet, creating new data sources and remote‑control possibilities.

  • Impact on everyday life: AI‑driven recommendation systems, XR in classrooms and training, IoT in smart homes and health monitoring.

1.8 Software–hardware interaction

  1. Application request – An application (e.g., a word processor) sends a request such as “print this document”.

  2. Operating‑system handling – The OS receives the request, checks permissions and determines which device driver is needed.

  3. Device‑driver translation – The driver converts the OS request into hardware‑specific commands or signals (e.g., a series of electrical pulses for the printer).

  4. CPU execution – The CPU executes the machine code, accessing RAM for temporary data, using the appropriate bus to reach the peripheral, and finally the hardware carries out the action.

  5. Feedback – The hardware returns status information (e.g., “print complete”) which the driver passes back to the OS and then to the application.

1.9 Comparison of System Software and Application Software

AspectSystem SoftwareApplication Software
PurposeManages hardware, provides a platform for other programmes.Enables users to perform specific tasks (e.g., writing, communicating, designing).
Typical tasksAllocate memory, schedule processes, control peripherals, run utilities.Create documents, browse the web, edit photos, analyse data.
Key examplesOperating systems (Windows, macOS, Linux), device drivers, utility programmes, firmware/BIOS.Microsoft Word, Google Chrome, Photoshop, Zoom, AutoCAD, PhET simulations.
Visibility to the userRuns largely in the background; interaction is indirect.Direct interaction; users launch and operate them.
DependencyCan operate without application software (e.g., a computer can boot to a command prompt).Requires system software (OS, drivers, firmware) to run.
InstallationUsually pre‑installed on a computer; updates are provided by the manufacturer or OS vendor.Installed by the user as needed; may be purchased or downloaded.
Examples of sub‑categoriesDevice drivers (e.g., printer driver), utility programmes (antivirus, backup).Productivity, communication, multimedia, educational, business, control/measurement, CAD, video‑editing.

1.10 Key points to remember

  • Hardware provides the physical platform; software gives it purpose.

  • System software (OS, drivers, utilities, firmware) is the foundation on which application software runs.

  • The four main hardware components are CPU, internal memory (RAM + ROM), I/O devices, and backing storage (magnetic, optical, solid‑state).

  • Operating‑system families (desktop, mobile, server) differ in typical use, strengths and limitations.

  • OS interfaces – CLI, GUI and touch/gesture – each have distinct advantages and disadvantages.

  • Application software is grouped into categories such as productivity, communication, multimedia, educational, business, control/measurement, CAD and video‑editing.

  • Emerging technologies (AI, XR/VR/AR, IoT) are extending how software interacts with the real world and influencing everyday life.

  • Understanding the software‑hardware interaction chain helps diagnose problems and appreciate how a simple request becomes a physical action.

Suggested diagram: Layered model – Application Software → Operating System → Device Drivers → Firmware → Hardware (CPU, Memory, Storage, I/O devices).

1 “Firmware” definition and examples taken from ISO/IEC 24773‑1:2008 – Information technology – Software – Vocabulary.