INFORMATION TECHNOLOGY (IEB) EXAM PREP.
THEORY NOTES
This document is set up in terms of Appendix G of the IEB’s SAGS document for IT as of 2022; I do not claim any definitions or explanations as
work of my own and don’t claim this intellectual property to be mine. This is merely a compilation of various sources’ definitions and
explanations to assist one in their preparation. No profit should be drawn from this document.
System Technologies
Hardware and Software
● Hardware is the physical components of a computer that runs and stores the
software on the computer, e.g. CPU, RAM
● Software is a set of computer programs and associated documentation and data or
a set of instructions that tell a computer what to do, e.g. Microsoft Word
● ICT System
○ Information and Communication Technology
○ A term used to describe systems that incorporate electronic technologies
and techniques to manage, capture, transmit and display information and
knowledge
● Computers are devices, usually electronic, that processes data according to a set of
instructions
● Input Processing Output (IPO) Model
○ represents a system in three stages: input, process and output
○ Input is achieved by giving the system data to process
○ Processing occurs when the computer interprets and executes the
information given as an input
○ Outputs are the result produced by the system after processing
● Advantages and disadvantages of using computers
1
, Advantages Disadvantages
Speed - Computers can make High cost - computers are expensive
calculations and logical comparisons
way faster than any human being
Accuracy - computers can’t make Takes over human jobs - computers
mistakes if the code is functioning and take jobs that no longer need to be
the data inputted is correct performed by humans
Repetitiveness - computers can do the The waste produced by computers -
same, tedious job for a long period of new computers are constantly
time while humans may become produced which leads to older ones
mentally fatigued being thrown away and
Versatility - a computer can perform Health problems - computers have a
many functions with the help of certain negative impact on your eyes, neck and
software back
● Data
○ Collection of facts
○ Raw and unorganised
○ It’s meaningless on its own
● Information
○ Facts that are put into context
○ Organised and analysed
○ It’s meaningful seeing that it is data that has been interpreted and analysed
● System types
○ Laptops = portable personal computers (PC)
○ Desktops = PCs designed for regular use at a single location on or near a
desk due to its size and power requirements
○ Server = a computer or computer program which manages access to a
centralised resource or service in a network
2
, ○ Embedded computers = hardware and software that is designed to perform
a highly specific function, e.g. a camera of a washing machine's embedded
computers will not be the same since they perform very different functions
○ Smart wear = wearable technology that monitors the wearer’s physical
activity and condition. Smart wear usually use bluetooth to connect to a
smartphone
○ Tablets = portable, touchscreen devices with a rechargeable battery; usually
smaller than a laptop but larger than a smartphone
○ Smartphones = portable computer devices that combine mobile telephone
and computing functions into one unit
○ Single board computer (SBC) = a complete, functioning computer in which
the microprocessor, input/output functions, memory, and other features are
all built on a single circuit board, with no expansion slots for peripherals, e.g.
Raspberry Pi and Arduino
● Mobility/Portability
○ Most portable in descending order: smart wear, smartphones, tablets,
laptops, desktops, servers
● Processing Power
○ Processing power highest to lowest: server, supercomputer, desktop, mobile
● Operating Systems
○ The main control program in a user’s device
○ Creates a user interface
○ Load and run programs
○ Manage resources
○ Acts as an interface between hardware and application programs
○ e.g. Desktop: Windows, Linux, macOS
○ e.g. Mobile: Android, iOS, Windows Phone
○ e.g. Embedded OS: OSs found in ATMs, electric vehicles, cameras
● Application software
○ Stand-alone applications = software that don’t require other applications in
order to work, e.g. Notepad, MS Word
○ Network applications = applications that run on one host, providing
communication to other applications on a different host, e.g. a web browser
3
, ● Main Hardware components of typical computing devices
○ CPU; made up of the CU, ALU and registers
○ Primary Storage like RAM, BIOS and ROM
○ Secondary Storage like Mechanical Hard Disk Drives (HDDs), Solid State
Drives (SSDs), SD Cards and flash drives
○ Input devices like pointing devices (mouse), keyboards, scanners,
microphones, biometric devices
○ Output devices like monitors, printers, speakers
○ Ports like USB and HDMI
○ Most of the above mentioned devices connect to the motherboard
● CPU Design
○ Registers
■ Stores current instructions and its data
■ Current instructions are broken into segments and individually stored
■ Are made from extremely fast and expensive SRAM (Static RAM);
SRAM have no capacitors and are thus constantly refreshed which
leads to a higher access time (faster access)
■ 32- bit computers have to process 64-bit numbers in 2 stages,
therefore a 64-bit computer has better performance. Note that a
64-bit computer isn’t necessarily twice as fast as a 32-bit; some 64-bit
code has higher memory consumption that lowers the performance
○ Control Unit (CU)
■ Controls the execution of each instruction
■ Sends read & write signals to the memory
■ Data fetched from memory is stored in either the CU or ALU
○ Arithmetic Logic Unit (ALU)
■ Calculations & logical comparisons take place here
■ The accumulator is the register that results of each execution
■ Data is loaded from the RAM to accumulator and saved from
accumulator to RAM
4
THEORY NOTES
This document is set up in terms of Appendix G of the IEB’s SAGS document for IT as of 2022; I do not claim any definitions or explanations as
work of my own and don’t claim this intellectual property to be mine. This is merely a compilation of various sources’ definitions and
explanations to assist one in their preparation. No profit should be drawn from this document.
System Technologies
Hardware and Software
● Hardware is the physical components of a computer that runs and stores the
software on the computer, e.g. CPU, RAM
● Software is a set of computer programs and associated documentation and data or
a set of instructions that tell a computer what to do, e.g. Microsoft Word
● ICT System
○ Information and Communication Technology
○ A term used to describe systems that incorporate electronic technologies
and techniques to manage, capture, transmit and display information and
knowledge
● Computers are devices, usually electronic, that processes data according to a set of
instructions
● Input Processing Output (IPO) Model
○ represents a system in three stages: input, process and output
○ Input is achieved by giving the system data to process
○ Processing occurs when the computer interprets and executes the
information given as an input
○ Outputs are the result produced by the system after processing
● Advantages and disadvantages of using computers
1
, Advantages Disadvantages
Speed - Computers can make High cost - computers are expensive
calculations and logical comparisons
way faster than any human being
Accuracy - computers can’t make Takes over human jobs - computers
mistakes if the code is functioning and take jobs that no longer need to be
the data inputted is correct performed by humans
Repetitiveness - computers can do the The waste produced by computers -
same, tedious job for a long period of new computers are constantly
time while humans may become produced which leads to older ones
mentally fatigued being thrown away and
Versatility - a computer can perform Health problems - computers have a
many functions with the help of certain negative impact on your eyes, neck and
software back
● Data
○ Collection of facts
○ Raw and unorganised
○ It’s meaningless on its own
● Information
○ Facts that are put into context
○ Organised and analysed
○ It’s meaningful seeing that it is data that has been interpreted and analysed
● System types
○ Laptops = portable personal computers (PC)
○ Desktops = PCs designed for regular use at a single location on or near a
desk due to its size and power requirements
○ Server = a computer or computer program which manages access to a
centralised resource or service in a network
2
, ○ Embedded computers = hardware and software that is designed to perform
a highly specific function, e.g. a camera of a washing machine's embedded
computers will not be the same since they perform very different functions
○ Smart wear = wearable technology that monitors the wearer’s physical
activity and condition. Smart wear usually use bluetooth to connect to a
smartphone
○ Tablets = portable, touchscreen devices with a rechargeable battery; usually
smaller than a laptop but larger than a smartphone
○ Smartphones = portable computer devices that combine mobile telephone
and computing functions into one unit
○ Single board computer (SBC) = a complete, functioning computer in which
the microprocessor, input/output functions, memory, and other features are
all built on a single circuit board, with no expansion slots for peripherals, e.g.
Raspberry Pi and Arduino
● Mobility/Portability
○ Most portable in descending order: smart wear, smartphones, tablets,
laptops, desktops, servers
● Processing Power
○ Processing power highest to lowest: server, supercomputer, desktop, mobile
● Operating Systems
○ The main control program in a user’s device
○ Creates a user interface
○ Load and run programs
○ Manage resources
○ Acts as an interface between hardware and application programs
○ e.g. Desktop: Windows, Linux, macOS
○ e.g. Mobile: Android, iOS, Windows Phone
○ e.g. Embedded OS: OSs found in ATMs, electric vehicles, cameras
● Application software
○ Stand-alone applications = software that don’t require other applications in
order to work, e.g. Notepad, MS Word
○ Network applications = applications that run on one host, providing
communication to other applications on a different host, e.g. a web browser
3
, ● Main Hardware components of typical computing devices
○ CPU; made up of the CU, ALU and registers
○ Primary Storage like RAM, BIOS and ROM
○ Secondary Storage like Mechanical Hard Disk Drives (HDDs), Solid State
Drives (SSDs), SD Cards and flash drives
○ Input devices like pointing devices (mouse), keyboards, scanners,
microphones, biometric devices
○ Output devices like monitors, printers, speakers
○ Ports like USB and HDMI
○ Most of the above mentioned devices connect to the motherboard
● CPU Design
○ Registers
■ Stores current instructions and its data
■ Current instructions are broken into segments and individually stored
■ Are made from extremely fast and expensive SRAM (Static RAM);
SRAM have no capacitors and are thus constantly refreshed which
leads to a higher access time (faster access)
■ 32- bit computers have to process 64-bit numbers in 2 stages,
therefore a 64-bit computer has better performance. Note that a
64-bit computer isn’t necessarily twice as fast as a 32-bit; some 64-bit
code has higher memory consumption that lowers the performance
○ Control Unit (CU)
■ Controls the execution of each instruction
■ Sends read & write signals to the memory
■ Data fetched from memory is stored in either the CU or ALU
○ Arithmetic Logic Unit (ALU)
■ Calculations & logical comparisons take place here
■ The accumulator is the register that results of each execution
■ Data is loaded from the RAM to accumulator and saved from
accumulator to RAM
4
