in-depth set of Grade 11 CAT Theory study notes based on study guide sections:
Systems Technologies, Social Implications, Internet & Network Technologies,
Solution Development, and Information Management.
These notes are clear, detailed, and exam-focused ideal for your CAT Theory
preparation.
CAT THEORY – GRADE 11
In-Depth Study Notes
1. SYSTEMS TECHNOLOGIES
Overview
Systems technologies refer to the hardware and software components that make
up a computer system and determine its performance, reliability, and usability.
1.1 Hardware Components
a) Input Devices
Used to enter data into a computer.
Examples:
• Keyboard, mouse, scanner, microphone, webcam, barcode reader.
b) Output Devices
Display or present processed data.
Examples:
• Monitor (LCD, LED), printer (laser, inkjet), speakers, projector.
c) Storage Devices
Store data and programs permanently or temporarily.
Types:
• Primary storage: RAM (volatile), ROM (non-volatile).
• Secondary storage: Hard drives (HDD/SSD), USB flash drives, memory
cards.
• Optical storage: CDs, DVDs, Blu-ray discs.
• Cloud storage: Online services like Google Drive, Dropbox.
,d) Processing
• CPU (Central Processing Unit):
o Control Unit (CU) – directs operations.
o Arithmetic Logic Unit (ALU) – performs calculations.
o Registers – high-speed memory inside CPU.
o Clock speed (GHz) – determines how many operations per second.
o Cores – multiple cores allow multitasking.
e) Motherboard
• Connects all components.
• Contains CPU socket, RAM slots, BIOS/UEFI chip, and ports.
1.2 Software Components
a) System Software
Runs and manages hardware.
• Operating system (OS): Manages files, memory, hardware, user interface
(Windows, macOS, Linux).
• Utility programs: Virus scanners, disk cleanup, backup utilities.
• Device drivers: Allow hardware to communicate with OS.
b) Application Software
Used to perform user tasks.
• Productivity: Word processors, spreadsheets, presentations.
• Specialized: CAD, accounting, photo editing.
• Custom-developed: Built for a specific organization’s needs.
c) Open Source vs Proprietary Software
Type Description Example
Open Source Free to use and modify Linux, LibreOffice
Proprietary Owned and licensed Microsoft Office, Adobe Photoshop
, 1.3 System Performance
Factors influencing performance:
• CPU speed & number of cores.
• Amount of RAM.
• Type of storage (SSD faster than HDD).
• Graphics card capability.
• Network speed.
• Software efficiency.
Improving performance:
• Close unused programs.
• Upgrade RAM or SSD.
• Regularly clean temporary files.
• Update drivers and OS.
1.4 System Security
• Antivirus software – detects malware.
• Firewall – prevents unauthorized access.
• User authentication – passwords, biometrics.
• Backups – protect against data loss.
• Updates/Patches – fix security vulnerabilities.
Exam Tip
Know the function of each component, examples of hardware & software, and
ways to improve system performance & security.
2. INTERNET & NETWORK TECHNOLOGIES
Overview
Networking connects computers to share data, resources, and communication.
, 2.1 Types of Networks
Type Description Example
PAN Personal Area Network Bluetooth between phone & laptop
LAN Local Area Network School computer lab
MAN Metropolitan Area Network City network
WAN Wide Area Network Internet
2.2 Network Devices
• Router: Connects multiple networks and directs data.
• Switch: Connects devices within a LAN efficiently.
• Hub: Sends data to all connected devices (less efficient).
• Access Point: Connects wireless devices to network.
• Modem: Connects network to the Internet.
2.3 Network Topologies
• Bus: One main cable; easy to set up, but failure stops all communication.
• Star: All devices connect to a central switch/router.
• Ring: Devices connected in a circle.
• Mesh: Each device connects to many others; reliable but expensive.
2.4 Internet Concepts
• IP address: Unique number identifying a device on the network (IPv4 or
IPv6).
• DNS (Domain Name System): Converts website names to IP addresses.
• ISP (Internet Service Provider): Provides internet connection.
• Bandwidth: Data transfer capacity (measured in Mbps).
• Latency: Delay in data transfer.
2.5 Network Security
• Encryption: Secures data in transit.
• Firewalls: Block unauthorized access.
• VPN (Virtual Private Network): Creates a secure tunnel through the Internet.
Systems Technologies, Social Implications, Internet & Network Technologies,
Solution Development, and Information Management.
These notes are clear, detailed, and exam-focused ideal for your CAT Theory
preparation.
CAT THEORY – GRADE 11
In-Depth Study Notes
1. SYSTEMS TECHNOLOGIES
Overview
Systems technologies refer to the hardware and software components that make
up a computer system and determine its performance, reliability, and usability.
1.1 Hardware Components
a) Input Devices
Used to enter data into a computer.
Examples:
• Keyboard, mouse, scanner, microphone, webcam, barcode reader.
b) Output Devices
Display or present processed data.
Examples:
• Monitor (LCD, LED), printer (laser, inkjet), speakers, projector.
c) Storage Devices
Store data and programs permanently or temporarily.
Types:
• Primary storage: RAM (volatile), ROM (non-volatile).
• Secondary storage: Hard drives (HDD/SSD), USB flash drives, memory
cards.
• Optical storage: CDs, DVDs, Blu-ray discs.
• Cloud storage: Online services like Google Drive, Dropbox.
,d) Processing
• CPU (Central Processing Unit):
o Control Unit (CU) – directs operations.
o Arithmetic Logic Unit (ALU) – performs calculations.
o Registers – high-speed memory inside CPU.
o Clock speed (GHz) – determines how many operations per second.
o Cores – multiple cores allow multitasking.
e) Motherboard
• Connects all components.
• Contains CPU socket, RAM slots, BIOS/UEFI chip, and ports.
1.2 Software Components
a) System Software
Runs and manages hardware.
• Operating system (OS): Manages files, memory, hardware, user interface
(Windows, macOS, Linux).
• Utility programs: Virus scanners, disk cleanup, backup utilities.
• Device drivers: Allow hardware to communicate with OS.
b) Application Software
Used to perform user tasks.
• Productivity: Word processors, spreadsheets, presentations.
• Specialized: CAD, accounting, photo editing.
• Custom-developed: Built for a specific organization’s needs.
c) Open Source vs Proprietary Software
Type Description Example
Open Source Free to use and modify Linux, LibreOffice
Proprietary Owned and licensed Microsoft Office, Adobe Photoshop
, 1.3 System Performance
Factors influencing performance:
• CPU speed & number of cores.
• Amount of RAM.
• Type of storage (SSD faster than HDD).
• Graphics card capability.
• Network speed.
• Software efficiency.
Improving performance:
• Close unused programs.
• Upgrade RAM or SSD.
• Regularly clean temporary files.
• Update drivers and OS.
1.4 System Security
• Antivirus software – detects malware.
• Firewall – prevents unauthorized access.
• User authentication – passwords, biometrics.
• Backups – protect against data loss.
• Updates/Patches – fix security vulnerabilities.
Exam Tip
Know the function of each component, examples of hardware & software, and
ways to improve system performance & security.
2. INTERNET & NETWORK TECHNOLOGIES
Overview
Networking connects computers to share data, resources, and communication.
, 2.1 Types of Networks
Type Description Example
PAN Personal Area Network Bluetooth between phone & laptop
LAN Local Area Network School computer lab
MAN Metropolitan Area Network City network
WAN Wide Area Network Internet
2.2 Network Devices
• Router: Connects multiple networks and directs data.
• Switch: Connects devices within a LAN efficiently.
• Hub: Sends data to all connected devices (less efficient).
• Access Point: Connects wireless devices to network.
• Modem: Connects network to the Internet.
2.3 Network Topologies
• Bus: One main cable; easy to set up, but failure stops all communication.
• Star: All devices connect to a central switch/router.
• Ring: Devices connected in a circle.
• Mesh: Each device connects to many others; reliable but expensive.
2.4 Internet Concepts
• IP address: Unique number identifying a device on the network (IPv4 or
IPv6).
• DNS (Domain Name System): Converts website names to IP addresses.
• ISP (Internet Service Provider): Provides internet connection.
• Bandwidth: Data transfer capacity (measured in Mbps).
• Latency: Delay in data transfer.
2.5 Network Security
• Encryption: Secures data in transit.
• Firewalls: Block unauthorized access.
• VPN (Virtual Private Network): Creates a secure tunnel through the Internet.
