2. Stand Alone
 Computers can be used on their own
without being connected to a network
but all computers now have the
capability to connect with a network.

3. Local Area Network
 A Local Area Network ( LAN) is a small
network in a single room, building or
site. Examples are:
 A school network
 A network in an office
 Connecting computers together to play
games at home.
 The computers can be linked using
copper cables or by a wireless
connection.

5. Wiring
Name Description
Twisted Pair This cable consists of two copper
wires twisted around each other.
Widely used because it is cheap and
capable of transmitting data at speeds
of 100 Mbps
Coaxial Not so commonly used as it is more
expensive.
It is used where there is lots of
interference that can corrupt data
because it has a protective shield to
prevent interference.
Fibre-Optic Fibre - Optic cable is made up of fine
strands of glass that transmit data as
pulses of light.
Fibre optic cable transmits at very high
speeds.
It doesn’t loose data because of
interference and is very secure.
It is very expensive to install.

6. Wireless
 Wireless networks use radio waves,
microwaves or infrared light to transmit
data.
 All you need is a transmitter / receiver in
every machine and a central device,
such as a wireless router; to pass the
data around the network.

7. Advantages to wireless
 Wireless networks are easy to install, as
there is no need for cables.
 You can move around when you work.
 Reasonably fast transmission speeds (
though slower compared to physical
cables)

8. Disadvantages to wireless
 Very vulnerable to hackers who can ‘tap
in’ to signals.
 Care is needed when setting up network
security if you don’t want other to access
your files or use your internet
connection.

9. The Internet
 The Internet is a global system of interconnected computer
networks.
 It has a number of different elements:
 The World Wide Web which is made up of multimedia
web pages that are stored on computers across the
world. Web pages hold text, sound, graphics, animations
and videos. These are linked by hyperlinks.
 Search engines to help users find their way around the
internet.
 Forums and chatrooms where you can meet people and
discuss all sorts of topics.

10. What is cloud storage?
 Video

11. Local Vs Cloud
 Businesses now have the choice of
buying and installing their own computer
hardware and software, and paying for
network connections, maintenance and
updating, or they can use the ‘Cloud’.
 This means they can rent equipment,
software, storage facilities and access to
the internet on a pay – as – you –go
basis.

12. Cloud Customers Local / non-Cloud users
Do not own the physical infrastructure, they are
owned by the Cloud Computing provider.
Own their own computer, backing storage
and wired or wireless connection equipment.
Can rent storage space on servers.
Customer can have a contract that enables them to
decide how much storage space they need for their
data.
This arrangement can be flexible and scaled.
Own their own hard drives, optical storage
and servers, which they have to maintains
and update.
Can have access to powerful networks without
great initial expense.
A business does not need to spend a large amounts
of money buying and installing systems.
Must bear the initial costs in buying
computers, backing storage and software,
which can be very high.
Can access a wide range of application software
and software for developing applications without
paying or installing.
Need to pay for and install all the software
required.
Have access to technical support, which is standard
to the service.
Need to provide/ pay for technical support.
Are billed for their service based on either time they
spend using the network or on a monthly or
quarterly basis. It is flexible.
Must bear the high initial setup costs before
the business can begin to use the system.
May have what is called a hybrid cloud system
where important data is stored locally.
Security concerns mean that some customers keep
what is called ‘mission critical data’ in computer
storage.
Are responsible for their own security. They
do not have the worry that data stored on the
‘Cloud’ can be hacked.

13. Client/Server
 Clients are workstations
 Servers are central computers
 Servers have:
 powerful processors
 Large memory capacity
<- NICs Ex2 ->

14. Client/Server
 The servers provide the resources for the
computers { clients} connected to the
network for example:
 Printer servers
 File Server
 Proxy server

15. Client/Server
 In a client server network it is possible to :
 organise Security for the whole network
 organise Backups for all the data on the
network
 control who can access the network by setting
up accounts {with IDs and passwords}

16. Peer to Peer network
 In a peer to peer network there is no
central server.
 The computers are linked together to
enable them to send and receive data.
 Each computer must back up its own data
and organise its own security

17. Peer to Peer Network

18. Peer to Peer network
 Since there is no centrally organised
security of backup system on a Peer to
Peer network:
 They are only suitable for ‘trusting’
environments’ e.g. home use.
 They are not suited to commercial or
business use.