Section 4 - Networks and the effects of using them Flashcards
What is a computer network?
A computer networks consists of 2 or more computers or electronic devices such as printers that have been linked together
What do networks enable us to do?
Share files
Send emails to each other
Share resources
How are networked computers joined together?
Cables
Radio signals
Telephone lines and satellites
Advantages of computer networks
Resources such as printers, scanners and internet can be shared
Files and data can be shared
Easy to communication with people on the network
Access our data from any computer
Data can be backed up to a separate computer for security
Access huge amount of information and files
Disadvantages of computer networks
If part of the network fails, the whole network can break down
Viruses can spread across the network very easily and quickly
If a computer on the network is hacked into then all other computers are prone to attack
What are the two types of computers that make up a network?
Servers
Clients
What is a server computer?
Powerful computers that provide ‘services’ to the client computers on the network.
Services provided by server computers
Providing central storage
Sharing devices
Providing network security
Sharing internet connections
Different types of servers
File servers
Application servers
Printer servers
Proxy servers
What is a client computer?
A normal computer that is used to perform everyday tasks and to access info and programs from the server.
What are the types of computer networks?
LAN
WLAN
WAN
Bluetooth
LAN
Local Area Network
Usually located in a single room or small building.
Private and can only be accessed by people in the room/building.
e.g. a school network is only used by students of that school.
Ads + disads of LAN
Ads:
Save money as each computer can share resources
Files and data can be shared easily
Files and data can be accessed from any computer within the server
Data can be sent around very fast
Can be monitored easily
Disads: Viruses can spread very quickly Security can be an issue The network can become unusable if the main server computer breaks down Slow internet connections High initial cost
WLAN
Wireless Local Area Networks
Similar to LANs but they connect computers together wirelessly without cables.
e.g. home networks
Ads + disads of WLANs
Ads:
physically safer as no cables are needed
cheaper to set up than a WLAN
easier to add more computers
devices such as printers and scanners can be connected to the network easily
computers and devices can be used anywhere in the building
Disads:
some areas might not be able to pick up the signal
security can be an issue
wireless signals can be unreliable
data transfer is slower than LAN
signal range is limited, so useless in a large building
WAN
Wide Area Network
made up of computers and devices that are connected in a large geographical area
created by connecting lots of LANs and individual computers together
computers and devices can connect to a WAN using telephone lines, fibre-optic cables and satellite signals
need a router or a modem
e.g. the internet
Ads and disads of WANs
Ads:
computers can be connected over wide areas
files and data can be shard over a large area
users can communicate very quickly, over large areas
e-commerce
computers and devices can be used anywhere
Disads: security can be an issue easy to accidentally download viruses data is transferred across a WAN is a lot slower than a LAN monitoring a WAN is difficult
Bluetooth (WPAN)
Wireless Personal Area Network (WPAN)
devices can connect to each other between 1 and 100 metres away from each other
ads + disads of bluetooth
ads: very easy to connect not easy to disrupt works wirelessly so no messy cables very little power needed
disads:
limited signal range
slow data transfer
very secure
Internet
a computer network that connects computers worldwide
Intranet
a private network within a company and it is only available to staff members of the organisation
