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unit 5 Flashcards

1
Q

what is a network?

A

a set of interconnected devices designed to communicate with each other and share resources

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2
Q

what is a protocol?

A

a set of rules that define how devices communicate over a network

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3
Q

what is a standard?

A

a set of guidelines or frameworks that govern how a task should be performed or how a product should function

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4
Q

what is the need for standards in a network?

A

enable different network devices to work together
ensure data can be correctly interpreted
support network expansion and integration of new technologies

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5
Q

what are the internet protocols?

A

HTTP, HTTPS, SMTP, FTP, TCP, IP, UDP

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6
Q

how does HTTP protocol work ?

A

primary protocol for transferring web content
works as a request response protocol in a client-server model

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7
Q

how does HTTPS protocol work ?

A

same as HTTP but with encryption for security
used in online banking

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8
Q

how does SMTP work?

A

simple mail transfer protocol
standard for sending email messages between servers
used to send emails from a client to a server

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9
Q

how does FTP work?

A

file transfer protocol
used for transferring files from one host to another over a network
provides authentication and can manage file directories

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10
Q

how does IP work?

A

internet protocol
functions mainly by addressing and routing packets of data from the source to the target device

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11
Q

what is protocol layering?

A

the way network protocols are divided into layers, each which perform specific functions

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12
Q

what is the purpose of protocol layering?

A

modularity
interoperability
ease of updates
specialisation

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13
Q

explain modularity in layering

A

breaking complex process of networking into more manageable layers, easier to design/implement networks

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14
Q

explain interoperability in layering

A

layering allows different technologies to work together seamlessly,
do not need to know the details of how the structure of the network works

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15
Q

explain ease of updates in layering

A

changes can be made to one layer without affecting others
this makes updates and improvements easier to implement

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16
Q

explain specialisation in layering

A

each layer can be specialised to perform its functions without worrying about the specifics of other layers

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17
Q

what are the 4 layers in the TCP/IP model?

A

application
transport
internet
link

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18
Q

what is the application layer?

A

layer where communication process begins
layer interacts directly with software like web browsers

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19
Q

what is the transport layer?

A

receives data from the application layer
responsible for end to end communication between source and destination

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20
Q

what does the transport layer do?

A

breaks the data it receives down into smaller units called packets
each packet is assigned a port number
each packet is also labelled with a header containing info

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21
Q

what is the internet layer?

A

layer that receives packets from the transport layer

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22
Q

what does the internet layer do?

A

adds a header to each packet, including the sender’s IP address and the receiver’s IP address
responsible for routing each packet across the network using the IP addresses in the headers

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23
Q

what is the link layer?

A

layer that receives packets from the internet layer and prepares them for transmission

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24
Q

what does the link layer do?

A

translates the digital packets into electrical, optical or wireless signals that can be sent over the network
once the signal reaches the receiving end the network layer translates it back into digital packets

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25
what does the header of a packet contain?
26
what is an IP address?
a unique identifier for a device on a network they are used to deliver packets to the correct destination
27
what is the domain name system?
a directory of domain names that is used to translate human readable domain names to the numeric IP addresses that computers use
28
what happens when you type a URL into a web browser?
1. user enters URL of a website into the web browser 2. computer checks its local cache to see if it contains the IP address of the URL from a previous request 3. the web browser sends a query to a DNS server to translate the URL into an IP address 4. the DNS resolver checks its cache to see if it has the IP address for the requested domain. if not it sends the request to the DNS root servers 5. the root server directs the resolver to a top level domain server based on the extension of the URL like .com 6. the TLD server then provides the resolver with the IP address of the domain's authoritative DNS server 7. the resolver queries the DNS server for the IP address of the requested domain 8. the DNS server responds with the IP address 9. the web browser sends an HTTP request to the IP address it received 10. the server at the given IP address processes the request and sends back the data for the web page 11. the web browser renders the received data into the web page
29
why do we have the DNS?
without it we would have to remember the IP address of every site we want to visit
30
what is a LAN?
local area network contained within a small geographical location
31
what are the advantages of a LAN?
centralised management security file sharing
32
explain the advantages of a LAN
security - can secure its devices using firewalls, antivirus file sharing - allows users on the network to share resources like printers management - updates, back ups
33
what are the disadvantages of a LAN?
hardware fails -> network won't function more prone to attacks access to data and peripherals can be slow require maintenance to ensure software is up to date
34
what is a WAN?
wide area network over a large geographical area
35
what is packet switching?
breaking down data into smaller individual packets and sending them separately along different routes and then reassembles them at their destination
36
what is circuit switching?
creating a communication connection between 2 endpoints for the duration of a transfer of data
37
what is latency?
delay in network communications
38
what is a firewall?
hardware or software that is used to protect a network by monitoring traffic going into and out of the network from the outside world
39
what is a proxy server?
server which sits between a network and the internet
40
what are the functions of a proxy server?
caching, logging and monitoring traffic, security, privacy
41
how does a proxy server make use of caching?
can keep copies of data that has been downloaded from the internet Once the proxy receives a request for a file or website from the internet, a copy is stored on the proxy.
42
what are the benefits of proxy caching?
quicker for the users and keeps down the bandwidth being used on the internet connection.
43
disadvantage of proxy caching?
file or website on the proxy might get out of date.
44
how do proxy servers make use of logging network traffic?
a proxy can monitor data going into a network they can keep logs of all traffic in and out.
45
how do proxy servers make use of security?
proxies can be external to a network and used to fetch web pages the request comes from the proxy and therefore it is the proxy’s IP address that is logged on the website, not that of the user.
46
what is encryption?
the process of making data unreadable to a third party It has to be decrypted (by someone with the key) in order to be read
47
what is a NIC?
network interface card allows a computer to connect to a network
48
what is a router?
a device to connect networks to the internet receives and forwards data packets to the correct IP address
49
what is a hub?
connects other devices together to form a network. ✚ It broadcasts all data to all possible destinations. ✚ The correct destination will accept the data
50
what is a switch?
connects other devices together to form a network. ✚ It keeps track of the addresses of devices connected to each port. ✚ It directs data only through the port to which the destination device is connected.
51
what is a wireless access point?
A device that is connected to a wired network and then provides a wireless signal. ✚ Other devices can then use wireless to connect to a Wi-Fi network.
52
how are devices connected in a network physically?
cables shorter distances = copper cables longer distances = fibre optic wireless = radio waves
53
what is a client server model ?
computers act as servers provide services to users such as file storage, printing, internet access
54
why is a client server model typically favoured?
✚ client computers don't need to be powerful and can therefore be cheaper ✚ it makes it easier to make data and software accessible from anywhere in the network ✚ banks of servers can be combined to make best use of their potential ✚ separate functionality can be devolved to virtual servers or physical servers.
55
what is a peer to peer model?
- each computer on the network has equal status - generally a cheap way of implementing a network - a popular way on the internet to pass files between users without the need to go through servers. - useful way to make use of distributed computing to promote collaborative working.
56
what is HTML?
hypertext markup language used to define web pages
57
what do

tags do?

used for different levels of heading (different sizes)
58
what is a

tag?

paragraph tag
59
what is a
tag?
divider tag to divide the page into blocks
60
what is a
  • tag?
    • numbered lists
    61
    what is an
      tag?
    ordered list tag
    62
    what is an
      tag?
    unordered list tag
    64
    how do you insert an image in html?
    pic
    65
    what is a
    tag?
    creates forms to collect data have tags to decide what type of data is inputted
    66
    what is CSS?
    cascading style sheets defines the style and design of a web page
    67
    what is background-colour?
    specifies the background colour of an element. Usually used on tags to change the background colour of the whole page, or with
    tags to change just part of it
    68
    what is border colour?
    Specifies the colour of the border (borders tend to be used on div elements)
    69
    what is border style?
    Specifies the style of a border. Options include: dotted, dashed and solid. If not specified, the border style is none by default and therefore no border is shown
    70
    what is border width?
    Specifies the width of the border in pixels
    71
    what is color?
    Specifies the colour of text within an element
    72
    what is font family?
    Specifies the font of the text. While the exact font can be specified, this relies on it being installed on the end-user’s computer. Instead, or additionally, the ‘family’ name is often given so the nearest match can be selected if exact font is unavailable. (Examples of families include serif, sans-serif and monospace
    73
    what is font size?
    Specifies the size of the font. Size can be given in a number of ways including: em: the number of times bigger it is than the standard font on the page px: pixels %: the percentage of the size it is of the standard font on the page
    74
    what is height?
    Specifies the height of an element (usually a div). Usually given in pixels or as a percentage of the element it is within
    75
    what is width?
    Specifies the width of an element (usually a div). Usually given in pixels or as a percentage of the element it is within
    76
    what is Javascript?
    programming language embedded within html using