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chapter 6
Fichas del conjunto (57)
- 1Describe the ring topology?each device is connected to two other devices,which forms a ring for the messages to travel round. Message is sent in one direction until the intended recipient recieves it
- 2What are the advantages of this?Data is transferred quickly as it only travels in one direction so there no data collision
- 3What are its disadvantagesIf any cable fails or a device is faulty the whole network will go down
Often workstations will see data there is a risk of privacy and security - 4What is a protocol?Rules that define data transmissions. In order for devices to communicate they need to agree to certain properties. Otherwise errors would frequently occur as data would not be transmitted in different ways and nothing would be able to communicate
- 5What is ip addressing?assignment of an internet protocol address. This is a unique identifier that each node on a network has. Networks using protocals tcp/ip transmit data based on what there address says
It is unique to a network - 6What si a MAC addressmedia access control address - a unique identifier each device on a network has. It is manufactured into every network card and so cannot be changed like an up address
- 7Network security what is a user access levelpermissions users have on a network, usually the id of a user will have permissions linked to it. At the highest access level the user is able to access everything on a network. Prevents prom seeing info they are not meant to
- 8What si password protectionthe user must enter a password before they can access any data. prevents sensitive and private information from being accessed in a network
- 9What is encytionencoding data so that only people that are authorised can see it as it requires a key to make it readable
- 10Network policies what si the acceptable use policies?terms and rules of use enforced by the operator of a network. They often focus on damage and protection of equipment
- 11What is the disaster recovery policya plan in case something goes wrong in a network e.g a fire or a viral attack. Network operators will have a back up of the data which will probably be covered under a back up policy
- 12What is a failover recovery?if a piece of hardware stops working, a secondary back up device will take functionality to prevent network downtime
- 13What is archiving?networks keep archives that are not currently in use be may be at a later date e,g user info
- 14What si the internet?It is a world wide collection of computer network
- 15What is a modemIts a combination of modulation and demodulation. converts digital data from your computer to analogue data for transmissions along a telephone line. Provide access to the interntet
- 16What si the deference between a router and a huba router sends packets between a network where as a hub or switch sends packets over one network
- 17Whats is a domain name system?connects ip adresses and webpages. The name of a webpage is its domain name
- 18What do they operate within?client/ server network
- 19What is html?Hypertext mark up language-language used to create a webpage.web users read and interpret html code and present it visually to anyone who is viewing it. It si managed by the world wide web consortium
- 20What is compression?A reduction of a files physical size so it contains less bits of data. It will also take less time to download.
- 21What is lossy compression?some of the original data is removed from the file during compression in order to reduce the file size and file isn't same after compression
- 22What si losslessno data is lost but storage is made more efficient,identical pixel are grouped to save storage space. After compression it is the same as the original
- 23What is JPEG or JPG?Joint photographic experts group-
uses lossy compression for digital images - 24What is GIFGraphic interchange format can be used for one image or lots. uses lossless compression
- 25What is pdfPortable document format, stores files in read only view designed for compatibility of many devices
- 26MP3used for audio files and uses lossy compression, meaning the audio is not as good as the original, although it work be removing data that humans wouldn't usually hear
- 27What is MPEGa video version of mp3, lossy compression
- 28What si a computer network?connections between nodes that allow data to be exchanged
- 29What si a local area networka network that connects computers that are close to each other
- 30What is a wide area network?a network over a broader area such as the internet and often uses telephone lines. Wan is made up of individual lans
- 31Give some advantages of lan?can share files and data with other computers in a network
it can be shared and accessed by each workstation
Most data is stored on a file server so it can be backed up - 32Give some disadvantages of LAN?computer system network in lan are more susceptible to security issues-viruses can spread and a computer system can be hacked
Hardware required to connect lan can be expensive and complexed.
Specialised technicians may be needed to use it - 33What si a network packet?small amount of data that can be sent over a computer network. When something is transmitted over a network it is broken in to packets, at the destination packets can be resembled.
- 34What do you need to connect stand alone hardware to lanadditional hardware
- 35What is a switchHas lots of ports to connect devices into. It forwards packets to their intended destination using mac addresses of devices
- 36What is a hub?connects devices together but the packets of data are sent to everything in a network accept the sender(less efficient and private)
- 37What is a router?forwards packets to make sure they get to their given destination. Passes data through different networks. May foward packets from lan to isp and then on to the internet
- 38What is a wireless access point?allows connections to a wired network using wifi. an ap can be a stand alone part of a computer or it can be part of a router making it a wireless router
- 39What is a mac address?media access control- a unique identifier that each device on lan has
- 40What is a server? What is a client?provider of a service or resource
a requestor of a service from a server - 41Describe a client-server network?establishes a network with the server over lan or wan e.g when you connect to the internet the client is your web browser. When you access a website the site server provides the resource which will include the webpage content
- 42Give advantages and disadvantages?server (in lan) can back up and store data centrally allthough this can be expensive and hard to run
- 43What is a peer to peer network?has no central server each computer is equally responsible as opposed a server having more responsibilities than client. Each computer has the ability to work as a client or a server. Its used by wifi networks and other lan networks as well as some internet services
- 44give some advantages and disadvantagesIts used by wifi networks and other lan networks as well as some internet services. It has better security as it is harder to trace
- 45What is Topologyarrangement of nodes and connection in a network
- 46Describe a buswere all the client servers are connected to one cable. When a node communicates, the data is transmitted down the bus that all devices receive, but only intended recipients accept and process the message.
- 47Give some advantages and disadvantages?cheap and easy to use only a short quality cable is needed
f a buss fails thw whole network will fail to communicate. As more workstations are needed the performance of a network decreases due to data collection - 48Describe the star topology?most hime networks use it as it has a central connect point that could be a hub, switch or router. Each node is linked to the central connection point
- 49Give some advantages and disadvantages?reliable- if a cable or a device fails the others will be unaffected, high preforming no data collisions occur
Expensive to install, lots of cable is required and extra hardware - 50What is the external view of a computerthe user friendly face that the users of the database see. Usually designed as a set of forms
- 51Conceptual viewfor the database designer. Shows the components parts of a database and how they are constructed and fit together
- 52internal viewdata which is stored within the computer system
- 53What are acid rulesprotects a database from errors during a transaction
- 54Automicitymeans ythe transaction is either completely carried out or not at all
- 55consistencya transaction must take the database from one valid form to another
- 56isolationno transaction may interefere with another
- 57durabilityOnce a transactio is committed it must remain so , even in case of error or power failure
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- GCSE Science Fichas sobre chapter 6, creado por Eloise Bridges el 11/01/2017.
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- Eloise Bridges
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