Grade 12 CAT Study Notes Computer Applications Technology
TOPICS COVERED
1. Software and Hardware
2. Input and Output Devices
3. Types of Storage Devices
4. Network and Internet (Wired & Wireless)
5. Email
6. Excel Spreadsheet (SUMIFS, HLOOKUP & VLOOKUP)
7. Microsoft Access
8. HTML Web Design with Tables
GRADE 12 CAT
STUDY NOTES
Computer Applications Technology
Page 1 of 21
,Grade 12 CAT Study Notes Computer Applications Technology
1. Software and Hardware
1.1 Software
Software refers to programs and operating information used by a computer. It is the non-physical
component of a computer system.
Types of Software
Type of Software Description & Examples
System Software Controls and manages computer hardware. e.g. Operating
System (Windows, macOS, Linux), Device Drivers, Utilities
Application Software Programs used to complete specific tasks for the user. e.g.
Word Processors, Spreadsheets, Browsers
Utility Software Maintains and optimises the computer. e.g. Antivirus, Disk
Defragmenter, Backup tools
Open Source Software Source code is freely available for anyone to view, use or
modify. e.g. LibreOffice, Linux, Firefox
Proprietary Software Commercial software with restricted source code. A licence
must be purchased. e.g. Microsoft Office, Adobe Photoshop
Freeware Free to use but source code is not available. e.g. Skype, VLC
Media Player
Shareware Free trial version; payment required for full version. e.g. WinZip,
WinRAR
★ Exam Tip: Know the difference between Open Source, Freeware, and Proprietary
software — these are commonly tested!
Operating System (OS) Functions
• Manages hardware resources (CPU, memory, storage)
• Provides a user interface (GUI or CLI)
• Manages files and directories
• Handles input and output operations
• Provides security and access control
• Manages running programs (multitasking)
1.2 Hardware
Hardware refers to all the physical components of a computer — parts you can touch and see.
Main Categories of Hardware
Page 2 of 21
, Grade 12 CAT Study Notes Computer Applications Technology
Category Examples Function
Processing CPU (Processor) Carries out instructions and
calculations
Memory RAM, ROM, Cache Stores data temporarily or
permanently
Input Devices Keyboard, Mouse, Scanner Send data into the computer
Output Devices Monitor, Printer, Speakers Deliver results to the user
Storage Devices HDD, SSD, USB Drive Store data permanently
Communication NIC, Modem, Router Allows computers to connect and
communicate
CPU (Central Processing Unit)
• ALU (Arithmetic Logic Unit): Performs mathematical and logical operations
• CU (Control Unit): Directs the flow of data within the CPU
• Registers: Tiny, ultra-fast storage inside the CPU
• Cache Memory: Stores frequently used data for quick access
Key Terms to Remember
• Bit = smallest unit of data (0 or 1)
• Byte = 8 bits
• Kilobyte (KB) = 1 024 Bytes
• Megabyte (MB) = 1 024 KB
• Gigabyte (GB) = 1 024 MB
• Terabyte (TB) = 1 024 GB
• Clock speed = measured in GHz (the faster the better)
• RAM = Random Access Memory (volatile — lost when power off)
• ROM = Read Only Memory (non-volatile — permanent)
Page 3 of 21
TOPICS COVERED
1. Software and Hardware
2. Input and Output Devices
3. Types of Storage Devices
4. Network and Internet (Wired & Wireless)
5. Email
6. Excel Spreadsheet (SUMIFS, HLOOKUP & VLOOKUP)
7. Microsoft Access
8. HTML Web Design with Tables
GRADE 12 CAT
STUDY NOTES
Computer Applications Technology
Page 1 of 21
,Grade 12 CAT Study Notes Computer Applications Technology
1. Software and Hardware
1.1 Software
Software refers to programs and operating information used by a computer. It is the non-physical
component of a computer system.
Types of Software
Type of Software Description & Examples
System Software Controls and manages computer hardware. e.g. Operating
System (Windows, macOS, Linux), Device Drivers, Utilities
Application Software Programs used to complete specific tasks for the user. e.g.
Word Processors, Spreadsheets, Browsers
Utility Software Maintains and optimises the computer. e.g. Antivirus, Disk
Defragmenter, Backup tools
Open Source Software Source code is freely available for anyone to view, use or
modify. e.g. LibreOffice, Linux, Firefox
Proprietary Software Commercial software with restricted source code. A licence
must be purchased. e.g. Microsoft Office, Adobe Photoshop
Freeware Free to use but source code is not available. e.g. Skype, VLC
Media Player
Shareware Free trial version; payment required for full version. e.g. WinZip,
WinRAR
★ Exam Tip: Know the difference between Open Source, Freeware, and Proprietary
software — these are commonly tested!
Operating System (OS) Functions
• Manages hardware resources (CPU, memory, storage)
• Provides a user interface (GUI or CLI)
• Manages files and directories
• Handles input and output operations
• Provides security and access control
• Manages running programs (multitasking)
1.2 Hardware
Hardware refers to all the physical components of a computer — parts you can touch and see.
Main Categories of Hardware
Page 2 of 21
, Grade 12 CAT Study Notes Computer Applications Technology
Category Examples Function
Processing CPU (Processor) Carries out instructions and
calculations
Memory RAM, ROM, Cache Stores data temporarily or
permanently
Input Devices Keyboard, Mouse, Scanner Send data into the computer
Output Devices Monitor, Printer, Speakers Deliver results to the user
Storage Devices HDD, SSD, USB Drive Store data permanently
Communication NIC, Modem, Router Allows computers to connect and
communicate
CPU (Central Processing Unit)
• ALU (Arithmetic Logic Unit): Performs mathematical and logical operations
• CU (Control Unit): Directs the flow of data within the CPU
• Registers: Tiny, ultra-fast storage inside the CPU
• Cache Memory: Stores frequently used data for quick access
Key Terms to Remember
• Bit = smallest unit of data (0 or 1)
• Byte = 8 bits
• Kilobyte (KB) = 1 024 Bytes
• Megabyte (MB) = 1 024 KB
• Gigabyte (GB) = 1 024 MB
• Terabyte (TB) = 1 024 GB
• Clock speed = measured in GHz (the faster the better)
• RAM = Random Access Memory (volatile — lost when power off)
• ROM = Read Only Memory (non-volatile — permanent)
Page 3 of 21
