CAT theory Grade 10 – 12 (detailed summary-2023)
❖ Network
o A collection of computers and other devices that are connected either via a cable
or wirelessly
Server
♦ Powerful computer that provides shared resources in a network
❖ Advantages of a network
▪ - fast efficient communication
▪ - sharing resources
▪ - centralization of data
▪ - flexible access
▪ - leisure
▪ - increased control and security
Disadvantages of a network
- confidential data is vulnerable
- expensive
- harmful software can spread quickly
- network faults
PAN (Personal Area Network)
Organized around individuals with a range of a few meters; usually one computing
device pairs with one or more other devices.
Main purpose and main advantage: automate connection between mobile devices
Disadvantages: Range of a few meters; data transmission can be slow; peripheral
devices usually paired with only one computing device at a time.
HAN (Home Area Network)
Network within a home environment; uses wired or wireless connection methods
If set up wirelessly, security can be an issue - must address with password etc.
❖ Switch
Used to connect computers in a HAN (but not for internet access)
➢ Router
Allows computers to connect to networks like the internet; built in switch allows other
devices in HAN to 'talk' to each other and share internet connection
Connection methods
, PAN usually Bluetooth; HAN uses wired and wireless connection methods
Wired connection: Every network device must have a NIC (network Interface controller);
Connects to the switch/router via UTP cable (unshielded Twisted pair)
Wireless connections: Every network device must have a built-in wireless adapter; use
Wi-Fi feature of router
- software to control security/ communication usually built into operating system of
device
❖ Internet
Worldwide computer network consisting of computers and networks linked by wired
and wireless communication media
IP (Internet Protocol) address
Every device connecting to internet must have its own
ISP (Internet Service Provider)
Company with a permeant, fast connection to the internet; they sell
internet access and services for a monthly fee, e.g., MWEB
Wired connections
1. ADSL - permanent digital connect using a telephone line; connection split into
two channels, one for phone calls and one for, internet connection
2. Fibre - data transmitted along thin glass fiber tubes; much faster then ADSL
(copper)
Wireless connection
4G and 5G (LTE) - latest generations of cellular technologies; mobile access
Dongle plugs into USB port to connect device to cellular network for internet
access
Smartphones or tablet can create a personal hotspot to share its internet
connection
❖ WWW (World Wide Web)
Vast collection of hyperlinked, interactive documents called web pages
❖ Web page
A document on the we which can be viewed in a web browser created in
languages such as HTML, JavaScript, PHP and Python
Website
A group of related web pages stored at the same web address
❖ Network
o A collection of computers and other devices that are connected either via a cable
or wirelessly
Server
♦ Powerful computer that provides shared resources in a network
❖ Advantages of a network
▪ - fast efficient communication
▪ - sharing resources
▪ - centralization of data
▪ - flexible access
▪ - leisure
▪ - increased control and security
Disadvantages of a network
- confidential data is vulnerable
- expensive
- harmful software can spread quickly
- network faults
PAN (Personal Area Network)
Organized around individuals with a range of a few meters; usually one computing
device pairs with one or more other devices.
Main purpose and main advantage: automate connection between mobile devices
Disadvantages: Range of a few meters; data transmission can be slow; peripheral
devices usually paired with only one computing device at a time.
HAN (Home Area Network)
Network within a home environment; uses wired or wireless connection methods
If set up wirelessly, security can be an issue - must address with password etc.
❖ Switch
Used to connect computers in a HAN (but not for internet access)
➢ Router
Allows computers to connect to networks like the internet; built in switch allows other
devices in HAN to 'talk' to each other and share internet connection
Connection methods
, PAN usually Bluetooth; HAN uses wired and wireless connection methods
Wired connection: Every network device must have a NIC (network Interface controller);
Connects to the switch/router via UTP cable (unshielded Twisted pair)
Wireless connections: Every network device must have a built-in wireless adapter; use
Wi-Fi feature of router
- software to control security/ communication usually built into operating system of
device
❖ Internet
Worldwide computer network consisting of computers and networks linked by wired
and wireless communication media
IP (Internet Protocol) address
Every device connecting to internet must have its own
ISP (Internet Service Provider)
Company with a permeant, fast connection to the internet; they sell
internet access and services for a monthly fee, e.g., MWEB
Wired connections
1. ADSL - permanent digital connect using a telephone line; connection split into
two channels, one for phone calls and one for, internet connection
2. Fibre - data transmitted along thin glass fiber tubes; much faster then ADSL
(copper)
Wireless connection
4G and 5G (LTE) - latest generations of cellular technologies; mobile access
Dongle plugs into USB port to connect device to cellular network for internet
access
Smartphones or tablet can create a personal hotspot to share its internet
connection
❖ WWW (World Wide Web)
Vast collection of hyperlinked, interactive documents called web pages
❖ Web page
A document on the we which can be viewed in a web browser created in
languages such as HTML, JavaScript, PHP and Python
Website
A group of related web pages stored at the same web address
