Chapter 6 (abigail) ✅ Flashcards
What is a network?
A network consists of a number of computers linked together either by using cable or wireless technology. This allows computers on the network to share resources including hardware and software. Computers on a network can also communicate with each other.
What is a computer which is not connected to a network called?
A standalone computer
What is a LAN?
A Local Area Network which is spread over a small geographical area eg a building or an office.
What is a WAN?
A Wide Area Network which is spread over a large geographical area on a global scale and requires a telecommunications link, such as a fibre optic cable or a satellite, to allow computers on the network to communicate.
What are the advantages of using networks?
-Users can save their work on the file server & retrieve it on any computer within the network.
-Expensive hardware devices (eg a laser printer) can be shared by all computers on a network.
-When files are stored on a file server, it allows data to be shared throughout an organisation.
-Backing up data can be done at the file server which is quicker than backing up the files on each individual computer.
-Security can be managed centrally by controlling access to data & software amongst users.
-Installing software & updates onto the file server will allow al computers to access software quickly.
What are the disadvantages of using networks?
-If a software virus gets onto the network, it can quickly spread which affects all user data and the organisation’s software.
-When a large number of users are logged onto the network using large data files & different software applications, the network speed can slow down if there is a limit on the bandwidth.
-The setup costs may be expensive and additional hardware eg file servers, NICs, switches & routers have to be purchased.
-Staff costs are increased when a network is installed as additional staff have to ensure it is fully maintained.
Internet
A WAN which allows information to pass between computers linked to a global network; it is a method of transporting data and is also accessible to anyone with a communications link.
WWW
The World Wide Web is an application which uses the internet. (If worth more marks then mention URLs, HTML, webpages, http, etc.)
URL
Uniform Resource Locator: Each website has a unique URL on the WWW.
HTML
Hypertext Markup Language: The web authoring language which the webpages on a website are developed using.
Name of the first page of a website:
Homepage
What does it require to access website through the internet?
A communications protocol known as http (hypertext transfer protocol)
Intranet
A private network set up as a secure website, owned & managed by an organisation. It uses the same communications protocol as the internet but only authorised users (with a username and password) can access it. This allows employees to work remotely & be able to access documents securely. They are commonly used by schools to access resources & communicate easily. An advantage of this is that uploaded resources can be accessed & reviewed by all students 24/7.
Internet of Things
IoT is a phrase used to describe the future impact of the internet on how we live & work. The scope of the IoT is increasing as the cost of technology decreases, more WiFi enabled devices are developed & high-speed broadband technology becomes cheaper.
Describe WiFi:
-Means Wireless Fidelity
-Modern devices are manufactured with a builtin wireless adapter which allows the user to connect to a WiFi network.
-WiFi connections are made possible through radio waves & a wireless router; meaning there is no need from network cables.
-Can be used in workplaces, home, cafes, etc.
Give one advantage of WiFi:
Being able to set up networks without a need for cabling
Give one disadvantage of WiFi:
Signal strength varies depending on the device’s distance from the wireless r outer which leads to what is known as “black spots”
Describe Bluetooth:
-Uses short-range wireless technology (in the form of radio signals) to connect 2 devices together
-This allows data to be transferred between them
-This means they must be in close proximity
-To begin data transfer, the devices must be synchronised
-There is no need for a router or 3rd party provider, making it cheaper.
-Also uses less power than other wireless technologies
-Eg music through Bluetooth earphones or a Bluetooth keyboard.
Give an advantage of Bluetooth:
Cheaper & uses less power
Give a disadvantage of Bluetooth:
The devices must be in close proximity
Describe optical fibre:
-Uses very thin glass strands to send data at very fast transmission speeds.
-Data is transmitted as pulses of light.
-A fibre optic cable consists of a bundle of glass strands.
-Each strand carries one data signal meaning that many data signals can be sent simultaneously in the bundle.
Give one advantage of optical fibre:
Glass instead of copper means signals cannot be interfered with by hackers and (due to the greater bandwidth) a larger capacity of data can be sent over a period of time.
Give one disadvantage of optical fibre:
Very expensive to install & requires the use of repeaters for data to travel over longer distances.
Describe mobile communications technology:
-4G (generation technology) mobile-phone technology is capable of high-speed data access & high-quality video streaming using wireless technology on a global scale.
Give one advantage of mobile communications technology:
Has allowed mobile phone providers to expand access to multimedia applications at higher speeds on their networks & at the same time lowering the cost per bit for downloading data
Give one disadvantage of mobile communications technology:
-Hardware is expensive so it is focuses on areas with a larger population.
-4G uses more battery life.
-5G is more reliable & works across a greater range with greater speeds than 4G.
What is a NIC?
-A network interface card is an electronic circuit board that needs to be installed into a computer to enable it to be connected to a network.
-Each computer on the network must have its own dedicated NIC so that it can communicate with the file server and the other computers on the network.
-The NIC also provides a ‘port’ on the computer to allow a network cable eg Ethernet to be attached to the NIC.
-Portable computers (eg laptops) are supplied with a wireless network interface card (WNIC) provided by the manufacturer.
What are network cables?
-Connect a computer to a network
-They are plugged into the computer’s NIC & the. Connected to something else, eg a switch.
-Generally, they are made of copper and the data travels long the cask to & from the file server.
-They are classified into categories depending on speed of transmission eg CAT6 cabling typically has increased transmission performances compared to CAT5 cabling.
What are switches?
-Hardware devices which are single collection points for computers on a network.
-A switch allows a large number of computers to be connected to it directly using network cables.
-It checks the destination of data it receives & ensures that it is forwarded to the intended computer.
What are routers?
-Hardware devices which connect a number of networks together either by cable or wirelessly.
-Routers are situated at gateways where 2 or more networks connect.
-The router examines data as it passes then forwards that data using the most appropriate route to its destination.
-IP addresses are used to determine the route by which the data travels on.
-A router could be used at home to connect your laptop to the internet.
-Some routers can filter incoming & outgoing data with a firewall feature.
Describe a bus network:
-Terminator at each end of the backbone cable.
-All workstations connected via cables to the backbone.
-Data travels in both directions down the backbone & terminatrs stop signaled bouncing back onto the backbone.
-If a cable attached to the backbone fails, only that computer will fail to operate.
-If the backbone cable fails then the whole network won’t operate.
Describe a star network:
-All computers are connected via a cable to a central powerful computer called the filer serves.
-If a cable fails, it will only affect the computer it’s connected to & everything else will operate as normal.
-An additional computer cable be added with another cable
Describe a ring network:
-No central/ controlling device. Each computer is directly connected to 2 adjacent computers to form a ring.
-If one cable fails then the whole network is impacted.
-To add a new computer is more complex as the cable Ethernet 2 existing computers has to be broken & each part of the broken cable attached to the new computer.
