Computer Applications Technology Grade 12 Theory Book Notes

General Concepts

  • ICT (Information and Communications Technology): Technology that gives access to information through telecommunication, using computers or smartphones to access networks like the internet.
  • Different types of computers:
    • Server: a powerful computer used in networks for storing large data amounts.
    • Workstation: a computer for individual, business, or professional use that is more capable than a personal computer.
    • Personal computer: compact, inexpensive, and widely used.
    • Laptops: portable PCs with integrated display, keyboard, and touchpad, operated by battery.
    • Tablets: ultra-portable and generally cheaper than laptops with less processing power.
    • Smartphones: handheld computers using flash memory and touch-screen technology.
    • Embedded systems: stand-alone electronic hardware for dedicated tasks (e.g., ATMs).
  • Computers offer economic benefits like saving paper, labor, and communication costs.
  • Computers have enabled advancements in technology and science.
  • Basic principles of computer operation: input, output, processing, storage and communication.
    • Input: data is entered into the computer through devices like keyboards and touchscreens, converted into binary code.
    • Processing: the CPU uses binary code to perform calculations, displaying it in a way that makes sense to the user.
    • Storage: Input is stored in memory banks of the computer.
    • Output: the computer displays pixels from the raw data making it understandable to the user.

Why we Use Computers

  • Computers improve productivity and assist scientists to cure diseases. They can also help architect design and construct new buildings.
  • Saving Time.
  • Communication costs reduced.
  • Efficiency improved.
  • Saving labor.
  • Accuracy in medical procedures improves because of technology.
  • Reduce effort to perform activities by: using spreadsheets, letters using word processors, messaging via email, and application forms online.
  • Global communication enabled.

Data, Information Knowledge & Wisdom

  • Data is raw, unorganized numbers, signals, or facts.
  • Information refers to facts and numbers that have been organized so that they are useful to people.
  • Convergence: combining multiple technologies to deliver new products.
  • Smartphones incorporate phone, camera, video, GPS, and music player functionalities.

Social Implications Environmental

  • Data centers use significant electricity contributing to greenhouse gases.
  • Factories producing computers can increases pollution.
  • E-waste: discarded electronic devices contain toxic materials.
  • Health hazards of burning devices to extract materials.
  • Green computing involves designing, manufacturing, using, and disposing of hardware and software to reduce environmental impact.
  • Use EPEAT (Electronic Product Environmental Assessment Tool) to evaluate the environmental impact of computer products.

Hardware

  • Hardware components and their main functions:
    • Input devices: keyboards, mice, touchscreens, scanners, cameras, and microphones.
    • Processing devices: motherboard, CPU, GPU, RAM, and ROM.
    • Storage devices: Hard-disk drive (HDD), Solid-state drive (SSD), flash disk, memory cards, CD, DVD and Blu-ray disks.
    • Output devices: LCD monitors, television monitors, data projector/ DLP device, printer & headsets and speakers.
    • Communication devices: Router, modems and switches
  • Consider computer uses when buying.
    • Home users: browse the internet, use social networks, send emails, some work from home.
    • SOHO (small office or home office) users: mobility, battery life, screen resolution, and speed are important.
    • Mobile users: mobility, battery life and internet connection are key factors to them.
    • Power users: use computers with the highest processing capacity.
    • Disabled users: computer requirements depend on the type of disability.
  • Productivity, efficiency, accuracy, and accessibility increase due to computers.
  • Keyboards: pros - enables information entry; cons - typing mistakes.
  • Mouse: ideal and easy for desktop use.
  • Touch screen: dual acting as both input and output.
  • Touchpad: used when there is no flat surface for a mouse.
  • Digital cameras: stores digital information.
  • Webcams: low cost, high convenience.
  • Microphones: enables fast and efficient manner.

Risks of Input Devices

  • Keystroke logging.
  • Physical Injury
  • Pathogen transmission
  • Privacy issues

Storage Devices

  • Important to evaluate storage device
    • Storage capacity.
    • Storage speed.
    • Volatility
    • Reliability and durability.
  • Internal Hard Drives: have a large capacity of storage space.
  • External Hard Drives: protected by a case that is designed to prevent damage and are connected to the computer by using a USB cable.
  • Solid-State Drives: faster than mechanical ones with lower capacity though.
  • Flash Drives: compact therefore easily portable.
  • Optical disc drives: portable storage of CD, DVD and Blu-ray disks.

Communication

  • Router has ability to to connects data on and between networks.
  • Modems connect computers to a networks and internet.
  • Switch connect multiple computers on the same internal network.

Software Notes

  • Software: Collection of computer instructions that tells the computer how to perform specific tasks.
  • Application Software: Allows the user to perform a specific personal, educational, or business-related function such as; word-processing, spreadsheet, database Presentation software, email, document management and web browsers.
  • Word processing software: allows the user to compose, edit, format, save and print typed documents.
  • Spreadsheet Software: sorts arranges and analyses data in a table format.
  • Database software: creates and manages databases.
  • Presentation software: designed to create and edit presentations in the form of slide shows.
  • Email software: makes it possible for user to compose and send email messages and receive.
  • Document management software: allows the user to store, manage, and track electronic documents and images.
  • Web Browsers: software application that allows the user to access information on the internet.
  • Installed applications: Can be accessed on your computer without the need of internet connections.
  • Web-based applications: Software does not take up any disk space on the computer and can be used anywhere.
  • Voice-recognition software and Typing tutor or keyboarding are good software enhancing accessibility productivity.

System Software

  • System requirements refer to a list of hardware and software requirements that help the software function.

Software problems

  • Updating Software can lead to Read-only files.
    Risks of using flawed software includes security risks, under and no performance
  • User-centered design (UCD) is a 4 phase design process that prioritizes consumer focus and the needs of the users
  • Social implications: By selecting devices based on certain criteria

Network Notes

  • Networks: Is when series of independent computers have been connected with either a physical, or a wireless connection.
    They are incredibly powerful tools that are used on a daily basis by businesses and private users.
  • Wide-area network (WAN) is a network that covers a large geographical area such as: neighbourhood, a city, a country, or the world
  • The internet is computer network that consists of billions of connected devices, allowing people to share information, obtain entertainment, or chat to one another
  • Internet Services: Is when each type of internet service available and its responsible for transferring a specific type of information
  • Instant Messaging makes it possible for other instant messages to be delivered during internet connection.
  • VoIP: Converted sound into data and transmit over the internet to other receivers.
    *Scanners : Helps give pictures a good resolution quality
  • Web browsers make it easier to work without having use of devices and help you quickly navigate through screens and pages.
New technologies:

The newest technologies that have been introduced

  • Holographic Phone
  • 5G Connections
  • Block-chain Technology
Wireless devices: Saves space as there are no wires
  • Battery life might be an issue causing the device to stop working
    Aesthetically better than wired input devices Potential interference of other Wi-Fi signals might cause a decrease in performance
    Allows flexibility of use as you can use the device at a distance There might be some security issues as it is easier to keylog a wireless device
Social implications of Networks:
  • Software (and hardware and people) is what makes computers useful, but we need to be aware of potential hazards to our safety and society in general.
  • Computer related crimes
    • Theft of computer hardware: theft of keyboards, flash drives, routers, etc. Never leave you equipment unattended in public.
  • Software theft: Copying, distributing copyrighted media without permission. Do not download torrents.
  • Bandwidth: bandwidth is stolen when you are using their Wi-Fi without permission (i.e. if you don't pay for it). You may need to put a password your Wi-Fi to avoid this.
  • Security Issues : Computer and internet have led to a rise in malware for security attacks
    Averting security threats, some safeguards techniques against criminals and protection in technology during this social climate