Grade 12 IEB CAT Study Notes Curro

MODULE 1.1 – HARDWARE

INPUT DEVICES

Input devices allow users to enter data into a computer.

• Keyboard: Used to enter text and commands.
• Mouse: Controls the pointer and selects items.
• Touchscreen: A dual-purpose hardware that functions as both an input and output device.
• Scanner: Converts physical paper documents into digital storage files.
• Barcode Reader: Used to read and interpret barcode information.
• Microphone: Captures audio input.
• Webcam: Captures visual images and video.

OUTPUT DEVICES

Output devices present information to users.

• Monitor: Displays visual information on a screen.
• Printer: Produces physical hard copies of digital documents.
• Data Projector: Projects images or video onto a large screen or surface.
• Speakers: Outputs sound and audio.
• Headphones: Provide private listening for the user.

ERGONOMIC DEVICES

These devices are specifically designed to reduce physical strain and injury for the user.

Features of an ergonomic mouse:

• Supports a natural hand position.
• Reduces wrist strain.
• Improves comfort during long periods of use.

STORAGE DEVICES

Hard Disk Drive (HDD)

• Uses spinning magnetic disks to store data.
• Generally cheaper than Solid State Drives ($SSDs$).
• Offers larger storage capacities.
• Contains moving parts, making it more susceptible to damage.

Solid State Drive (SSD)

• Utilizes flash memory for storage.
• Significantly faster than $HDDs$.
• Highly durable due to having no moving parts.
• Lower power consumption.

Optical Storage Examples:

• $CD$
• $DVD$
• Blu-ray Disc

Flash Storage Examples:

• Flash Drive
• Memory Card

MODULE 1.2 – COMPUTER COMPONENTS

INTERNAL COMPONENTS

• CPU (Central Processing Unit): Often referred to as the brain of the computer; it performs calculations and executes instructions.
• RAM (Random Access Memory): Temporary memory that stores data currently in use. It is volatile memory, meaning data is lost when power is removed.
• GPU (Graphics Processing Unit): Responsible for processing graphics and video; essential for gaming and professional video editing.

PORTS

• USB (Universal Serial Bus): Used to connect a wide variety of peripherals and devices.
• HDMI: Transfers high-definition video and audio signals.
• Ethernet Port: Used for wired network connections.
• Audio Port: Connects sound devices like speakers or microphones.

FIRMWARE AND COMPATIBILITY

• Firmware: Software that is permanently stored on hardware.
  • Examples: $BIOS$, $UEFI$
• System Compatibility: The specific ability of hardware and software to work correctly with a particular operating system.

MODULE 1.3 – HEALTH, SAFETY AND GREEN COMPUTING

RSI (REPETITIVE STRAIN INJURY)

$RSI$ is caused by repetitive movements and maintaining poor posture for extended periods.

• Common Example: Carpal Tunnel Syndrome.
• Prevention Methods:
  • Take regular breaks.
  • Use ergonomic devices.
  • Maintain good posture.
  • Learn and use keyboard shortcuts to reduce mouse usage.

GREEN COMPUTING

Green computing involves using technology in environmentally friendly and sustainable ways.

• Examples of Green Computing Practices:
  • Duplex printing (printing on both sides of the paper).
  • Recycling printer cartridges.
  • Switching off devices entirely when they are not in use.
  • Investing in and using energy-efficient hardware.

MODULE 1.4 – DIGITAL MEDIA

VISUAL SPECIFICATIONS

• Resolution: The number of pixels displayed on a screen.
  • Example: $1920 \times 1080$
  • Impact of higher resolution: Sharper images and more visible detail.
• Aspect Ratio: The relationship between screen width and height.
  • Examples: $16:9$ and $4:3$
• Colour Depth: The number of bits used to represent colours.
  • Impact of higher colour depth: Provides more colours and better image quality.
• Contrast Ratio: The difference between the darkest black and the brightest white that a display can produce.
• DPI (Dots Per Inch): A measure of pixel density or print quality.
  • Impact: A higher $DPI$ results in better quality images and sharper printing.
• ISO Rating: Measures the camera sensor's sensitivity to light.
  • Impact: A higher $ISO$ provides better performance in low-light conditions but results in more image noise.

GPS (GLOBAL POSITIONING SYSTEM)

$GPS$ uses satellites to determine a precise location on Earth.

• Applications: Navigation systems and Geotagging.

INFORMATION PROCESSING CYCLE

1. INPUT: Data is entered into the system.
2. PROCESSING: Data is manipulated or calculated.
3. OUTPUT: Information is displayed to the user.
4. STORAGE: Information is saved for later use.

Cycle Example:

• Input: Scan a barcode.
• Processing: Check the product database.
• Output: Display the due date or price.
• Storage: Save the transaction record.

CONVERGENCE

Definition: The process of combining multiple technologies or functionalities into a single device.

• Examples: Smartphone, Smart $TV$.
• Case Study: Multifunction Printer: A multifunction printer is an example of convergence because it combines printing, scanning, copying, and faxing into one unit.

SOHO

Definition: $SOHO$ stands for Small Office Home Office.

Common Administrative Tasks in a SOHO environment:

1. Sending emails.
2. Bookkeeping.
3. Scheduling appointments.
4. Maintaining records.

MODULE 2.1 – SOFTWARE

WEB-BASED APPLICATIONS

• Examples: Gmail, Google Docs, Microsoft 365 Online.
• Advantages:
  • Accessible from anywhere with a connection.
  • Updates are automatic.
  • Platform independent (runs in any browser).
• Disadvantages:
  • Requires a stable Internet connection.
  • Potential security concerns.
  • Limited functionality for offline use.

SUBSCRIPTION-BASED SOFTWARE

Users pay recurring fees rather than a one-time purchase price.

• Payment Models: Monthly or Annual fees.
• Examples: Microsoft 365, Adobe Creative Cloud.

SOFTWARE TYPES AND TOOLS

• Office Suite Components: Word Processor, Spreadsheet, Presentation Software.
• Voice Recognition Software Advantages:
  • Faster text entry compared to typing.
  • Enables hands-free operation.
  • Greatly improves accessibility for users with disabilities.
• Educational Software Advantages:
  • Allows students to learn at their own pace.
  • Interactive learning experiences.
  • Provides immediate feedback on performance.
• MOOC (Massive Open Online Course): Large-scale online courses available through the Internet to a wide audience.

MAINTENANCE AND RISKS

• Software Patch: A small software update used to fix bugs, improve security, or enhance performance.
• Risks of Buggy Software:
  • System crashes.
  • Data loss.
  • Security vulnerabilities.

USER-CENTRED INTERFACE DESIGN GUIDELINES

1. Keep interfaces simple.
2. Use consistent layouts throughout the application.
3. Provide clear and concise instructions.
4. Make navigation easy and intuitive.

MODULE 2.2 – NETWORKS AND INTERNET

NETWORK DEFINITIONS

• Bandwidth: The maximum amount of data that can be transmitted in a given amount of time. Measured in $Mbps$ (megabits per second) or $Gbps$ (gigabits per second).
• WAN (Wide Area Network): A network that covers a large geographical area. The Internet is the most prominent example.
• VoIP (Voice over Internet Protocol): The technology used to make voice calls over the Internet.
  • Examples: Skype, Zoom, WhatsApp Calls.
  • Advantages: Cheaper call rates, support for video calling, and easier international communication.

COMPUTING MODELS

• Cloud Computing: Using remote servers hosted on the Internet to store, manage, and process data.
  • Examples: Google Drive, OneDrive, Dropbox.
  • Grid Computing: A system where many computers work together to solve extremely complex tasks.

CYBERSECURITY

THREATS

• Malware: Software specifically designed to damage or disrupt systems.
  • Examples: Virus, Worm, Trojan.
• Social Engineering: The practice of manipulating people into revealing confidential information.
• Identity Theft: The fraudulent practice of using another person's personal information.
• Phishing: Using fake emails or messages to steal sensitive information.
• Pharming: Maliciously redirecting users to fake websites even if they type the correct address.
  • Key Difference: Phishing relies on tricking the user into taking action; Pharming involves technical redirection.
• Click-jacking: A technique used to trick users into clicking on hidden links.
• Keylogger: Software that records every keystroke made on a device.
  • Threat: Used to steal passwords and sensitive banking information.
• Bots: Automated programs that can spread malware or participate in $DoS$ (Denial of Service) attacks.
• Skimming: Stealing banking or credit card information using hidden physical devices.
• Cyberattack: A deliberate attempt to damage, steal data from, or gain unauthorised access to computer systems.

DEFENCE AND SECURITY SIGNS

• Antivirus Software Functions:
  • Scans files for malicious code.
  • Detects potential threats.
  • Removes malware from the system.
  • Examples: Norton, McAfee, Bitdefender, Microsoft Defender.
• Identifying Secure Websites:
  • Look for $HTTPS$ in the address bar.
  • Check for the Padlock symbol.

IMPORTANT ABBREVIATIONS

• CPU: Central Processing Unit
• RAM: Random Access Memory
• GPU: Graphics Processing Unit
• USB: Universal Serial Bus
• OCR: Optical Character Recognition
• OMR: Optical Mark Recognition
• RFID: Radio Frequency Identification
• RSS: Really Simple Syndication
• DPI: Dots Per Inch
• VoIP: Voice over Internet Protocol
• RSI: Repetitive Strain Injury
• QR: Quick Response
• DIMM: Dual In-line Memory Module
• GPS: Global Positioning System
• WAN: Wide Area Network
• SSD: Solid State Drive
• HDD: Hard Disk Drive
• SOHO: Small Office Home Office
• GUI: Graphical User Interface

QUICK ANSWERS AND TEST DATA

• 1.1: Touchscreen
• 1.2: Ensure lighting is adequate
• 1.3: $7200\,RPM$
• 1.4: Create document → Insert border → Adjust settings → Save
• 2.1: Keylogger
• 2.2: ISO Rating
• 2.3: $DPI$
• 2.4: $GPS$
• 2.5: $DVD$
• 3.1: Virtual Reality
• 3.2: Aspect Ratio
• 3.3: System Compatibility
• 3.4: Colour Depth
• 3.5: $GUI$
• 4.1: $CPU$
• 4.2: $RSI$
• 4.3: $RFID$
• 4.4: $USB$
• CMYK Components:
  • Cyan
  • Magenta
  • Yellow
  • Key (Black)