CAT
THEORY
GRADE 12
(Based on Study Opportunities
Textbook)
,Table of Contents
Chapter 1.1 computers in our everyday lives.......................................................................3
.....................................................................................................................................................5
Chapter 1.2 Hardware devices............................................................................................6
Chapter 1.3 Hardware recommendations.........................................................................18
Chapter 1.4 software........................................................................................................23
Chapter 1.5 Systems and computer management.............................................................28
Chapter 2.1 Internet connections and services..................................................................34
Chapter 2.2 The dangers of computer crime......................................................................40
Chapter 2.3 E-communications.........................................................................................43
Chapter 2.4 The impact of technology...............................................................................47
.........................................................................................................................................51
,Chapter 1.1 computers in our everyday lives
Why do we use computers?
Efficiency, accuracy and reliability
Efficiency
Computers save : time, labour, resources, accuracy and reliability
Time:
-computers work faster than people
-computers work in ‘real time’ when tasks need to happen
Labour
-reduced labour involved in mentally intensive tasks
- used in repetitive physical tasks
- can perform tasks that are dangerous for people
Resources
- Computers can work more efficiently with resources (e.g. automatically switching
lights off to save electricity) , can monitor carbon emissions
Accuracy
- Accuracy that is repeatable is essential for e.g. mass production
- If software is correct, computer will be 100% accurate
Reliability
No external factors e.g. bored/tired
Communication
This together with reliability and accuracy allows us to:
- Eliminate time and distance as business constraints
- Communicate and share info in many different ways globally: can share info and
work on same info at same time
- Save on communication costs: no postage and cheap calls like Volp
- Interact socially on a world-wide scale e.g. SnapChat, Facebook
TYPES OF COMPUTER SYSTEMS
When choosing consider : how powerful, what it will be used for, size, software ( types of
operating systems= platforms)
Non portable computers
- Consist of system unit, screen, mouse, keyboard
- Large
- Generally more powerful than mobile computer
Desktop computer – if lower specifications cost less
Server – powerful computer that provides resources/ services to all computers
linked in a network
What is an entry level computer
Cheapest to buy in their range therefore low hardware specifications
Portable Computer
, - Uses a traditional operating system ( e.g. Windows, macOS)
- Portable i.e. hardware has all in one design (includes e.g. screen , keyboard, battery)
- Can use it at work and home
Description. comments
Laptop/notebook Screen size larger than Laptops can have same
12’’or 13’’ specifications as desktop
Portable computers but cost more than their
non -portable equivalents
Tablet Portable Similar to smartphone but
Touch screen or pen larger screen
sensitive screen Cant make cell calls or
send /get SMS
Longer battery life than
smartphone so can
read/watch video
Hybrid Computer Have a reversible screen Called ‘hybrids’ as they can
and normal keyboard be used as normal laptops
Screen is touch or pen or as tablets
sensitive
Also called ‘convertibles’
smartphone Cell phone that includes Computer in your pocket
operating system Instant access to email,
Ability to install and run internet etc
other programs Additional features like
Usually touch screen GPS/ video etc
interface
Phablet Smartphone with screen Midway bt smartphone and
size larger than 5’’ tablet
Can make calls like normal
smartphone
Larger screen size is
convenient
CATEGORIES OF USERS
1. Personal users= people who do not depend on their computers and do not spend a lot
of time using computer.
Personal users may use computer for:
- Limited office tasks
- Internet banking
- Email and browsing web
- Social networking
- Skype family/friends
- View/share photos
- Entertainment
2. SOHO= Small Office Home Office depends on type of business. May need entry level for
administration functions like;
THEORY
GRADE 12
(Based on Study Opportunities
Textbook)
,Table of Contents
Chapter 1.1 computers in our everyday lives.......................................................................3
.....................................................................................................................................................5
Chapter 1.2 Hardware devices............................................................................................6
Chapter 1.3 Hardware recommendations.........................................................................18
Chapter 1.4 software........................................................................................................23
Chapter 1.5 Systems and computer management.............................................................28
Chapter 2.1 Internet connections and services..................................................................34
Chapter 2.2 The dangers of computer crime......................................................................40
Chapter 2.3 E-communications.........................................................................................43
Chapter 2.4 The impact of technology...............................................................................47
.........................................................................................................................................51
,Chapter 1.1 computers in our everyday lives
Why do we use computers?
Efficiency, accuracy and reliability
Efficiency
Computers save : time, labour, resources, accuracy and reliability
Time:
-computers work faster than people
-computers work in ‘real time’ when tasks need to happen
Labour
-reduced labour involved in mentally intensive tasks
- used in repetitive physical tasks
- can perform tasks that are dangerous for people
Resources
- Computers can work more efficiently with resources (e.g. automatically switching
lights off to save electricity) , can monitor carbon emissions
Accuracy
- Accuracy that is repeatable is essential for e.g. mass production
- If software is correct, computer will be 100% accurate
Reliability
No external factors e.g. bored/tired
Communication
This together with reliability and accuracy allows us to:
- Eliminate time and distance as business constraints
- Communicate and share info in many different ways globally: can share info and
work on same info at same time
- Save on communication costs: no postage and cheap calls like Volp
- Interact socially on a world-wide scale e.g. SnapChat, Facebook
TYPES OF COMPUTER SYSTEMS
When choosing consider : how powerful, what it will be used for, size, software ( types of
operating systems= platforms)
Non portable computers
- Consist of system unit, screen, mouse, keyboard
- Large
- Generally more powerful than mobile computer
Desktop computer – if lower specifications cost less
Server – powerful computer that provides resources/ services to all computers
linked in a network
What is an entry level computer
Cheapest to buy in their range therefore low hardware specifications
Portable Computer
, - Uses a traditional operating system ( e.g. Windows, macOS)
- Portable i.e. hardware has all in one design (includes e.g. screen , keyboard, battery)
- Can use it at work and home
Description. comments
Laptop/notebook Screen size larger than Laptops can have same
12’’or 13’’ specifications as desktop
Portable computers but cost more than their
non -portable equivalents
Tablet Portable Similar to smartphone but
Touch screen or pen larger screen
sensitive screen Cant make cell calls or
send /get SMS
Longer battery life than
smartphone so can
read/watch video
Hybrid Computer Have a reversible screen Called ‘hybrids’ as they can
and normal keyboard be used as normal laptops
Screen is touch or pen or as tablets
sensitive
Also called ‘convertibles’
smartphone Cell phone that includes Computer in your pocket
operating system Instant access to email,
Ability to install and run internet etc
other programs Additional features like
Usually touch screen GPS/ video etc
interface
Phablet Smartphone with screen Midway bt smartphone and
size larger than 5’’ tablet
Can make calls like normal
smartphone
Larger screen size is
convenient
CATEGORIES OF USERS
1. Personal users= people who do not depend on their computers and do not spend a lot
of time using computer.
Personal users may use computer for:
- Limited office tasks
- Internet banking
- Email and browsing web
- Social networking
- Skype family/friends
- View/share photos
- Entertainment
2. SOHO= Small Office Home Office depends on type of business. May need entry level for
administration functions like;
