Types and Components of a Computer System

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Hardware and Software

Hardware is the physical component that makes up the computer system. E.g. Mouse, keyboard, printer, monitor, etc.

Internal hardware

The Central Processing Unit (CPU) is part of the computer that interprets and executes the commands from the computer hardware and software.

The motherboard is a printed circuit and it allows the processor and other computer hardware to function and communicate with each other.

Random Access Memory (RAM) is an internal chip where data is temporarily stored when running applications.


Read-Only Memory (ROM) is used to store information that needs to be permanent. Contain boot file to start up the computer called BIOS (Basic Input/Output System).

Video Card allows the computer to send graphical information to a video display device.

Sound Card is an integrated circuit board that provides a computer with the ability to produce sounds.

Internal Hard Disk Drive (HDD) / Solid State Disk (SSD) is the main internal storage to store OS, files, applications software.









Software is a general term for the programs that control the computer system. There are 2 types of software, application software, and system software.

Application software is a program that allows the user to do specific tasks, such as:

  • Word Processing to manipulate text documents
  • Spreadsheet to organize and manipulate numerical data
  • Database to organize, manipulate, and analyze data
  • Control and measuring software is designed to allow a computer or microprocessor to interface with sensors
  • Apps are typically run on mobile phones or tablets
  • Photo editing is to manipulate digital photographs stores on a computer
  • Video editing is to manipulate video to produce an edited video
  • Graphic manipulation is to allow bitmap and vector images to be changed

System software is a program that allows the hardware to run properly and allow the user to communicate with the computer, such as:

  • The compiler is to translate a program written in a high-level language (HLL) into machine code
  • Linkers is a computer program that takes one or more object files produced by a compiler and combines them into a single program that can be run on a computer
  • Device Driver is to enable hardware devices to communicate with the computer OS
  • Operating System (OS) is running in the background of a computer system, manages many of the basic functions.
  • Utilities are designed to carry out specific tasks on a computer

Operating Systems

Operating Systems (OS) to enable computer systems to function and to allow users to communicate with computer systems. General tasks of OS are:

      • Control of the operation of the input, output, and backing storage,
      • Supervising the loading, running, and storage of application programs,
      • Dealing with errors that occur in application programs,
      • Maintaining the security of the whole computer system,
      • Maintaining a computer log,
      • Allowing communion between the user and the computer system.
Command-Line Interface (CLI)

CLI requires users to type in instructions to choose options from menus, open software and etc.


  • The user is in direct communication with the computer,
  • The user is not restricted to a number of predetermined options,
  • It is possible to alter computer configuration settings.


  • The user needs to learn a number of commands to carry out basic operations,
  • All commands need to be typed in, which takes time and can be error-prone,
  • Each command must be typed in using the correct format, spelling, and so on,
  • It is more difficult to edit once commands are entered.
Graphical User Interface (GUI)

GUI allows the users to interact with a computer using pictures or icons rather than having to type in a number of commands.


  • The user doesn’t need to learn any commands,
  • It is more user-friendly, icons are used to represent applications,
  • A pointing device is used to click on an icon to launch the application.


  • It uses up considerably more computer memory,
  • The user is limited to the icons provided on the screen,
  • It needs an operating system.

Types of Computers

Personal Computer (PC) / Desktop is a general-purpose computer that is made up of a separate monitor, keyboard, mouse, and processor unit.


  • Spare parts and connections tend to be standardized, which usually results in lower costs
  • Tends to have a better specification
  • Power consumption is not critical
  • Less likelihood of being damaged because in a fixed location
  • Internet access is also more stable since they are not moved around


  • Not portable
  • More complicated with all of the components (cables, mouse, keyboard, etc.)
Laptop Computers is a portable computer where the monitor, keyboard, pointing device, and processor are all together in one single unit


  • Portability
  • Less complicated
  • Wi-fi based
  • Able to link into any multimedia system


  • Easier to steal
  • Limited battery life and heavy adaptor
  • Keyboard and pointing devices can be awkward to use

Key features:

  • High-definition, anti-glare displays
  • Front and back-facing cameras
  • Lower weight and longer battery life
  • Bluetooth connection
  • Flash memory
  • Sensors (proximity, accelerometer, etc.)


  • Very fast to switch on
  • Fully portable
  • Touch-screen technology
  • Can use several apps
  • Don’t generate any heat
  • Battery life is longer
  • Standby with low power


  • Limited memory
  • Expensive to run using the mobile network
  • Hard to type using the on-screen keyboard
  • Lack of drag and drop facility
  • Laptop support more types of file


Smartphones are a phone but with the operating system, that allowing them to run a number of computer application

Key features

  • Send/receive email
  • Surf the net
  • GPS
  • Calendar function
  • Streaming videos, music


  • Very small and lightweight
  • Make phone calls and connect to the internet
  • Wi-Fi and mobile network
  • Hundreds of Apps
  • Reasonable battery life


  • Small screens
  • Certain apps or activities might drain the battery quickly
  • Memory size is not large
  • Not all website features are compatible
  • Easier to lose
  • Slower transfer rate
Smartwatches are mini-computer on their wrist

Key features

  • Internet connectivity
  • Ability to make and take phone calls
  • Messaging via text or video
  • Weather forecast
  • Fitness and health-monitoring capability
  • GPS


  • More convenient than smartphones
  • Easy to use for monitoring fitness and health regimes


  • Large and bulky
  • Unattractive designs
Mainframes Computers is a very large and powerful computer system

Key features:

  • User several CPUs
  • Very fast processor speeds
  • Support multiple operating systems
  • Huge amounts of storage capacity
  • Huge internal memories
  • Operate using time-sharing or batch processing (often)


Impact of Emerging Technologies

  • Artificial Intelligence (AI) Biometric – Dynamic profiling
    Vision Enhancement

    • Low-Vision Enhancement Systems (LVES) using video technology through a headset connected to a computer
    • Night Vision Enhancement (NVE) amplifies light and visible light so that an image can still be seen in apparent darkness
  • Robotics – Drones for military use
  • Quantum Cryptography is based on the use of photons (lights) on their physical quantum properties to produce a virtually unbreakable cryptography system
  • Computer-Assisted Translation (CAT
  • 3D and holographic imaging is a technology that allows 3D images to be produced. It involves the user of:
    • A source of laser light
    • Interference of light
    • Light diffraction
    • Light intensity recording
  • Virtual reality is an artificial environment created by the software. Used in:
    • Military application – training to use a new tank
    • Education – looking inside an ancient building
    • Healthcare – diagnostic tool
    • Engineering – seeing how new designs will look
    • Scientific visualization – looking at molecular structures in chemistry










3-D and Holographic Imaging
Virtual Reality