Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A-Level Computing > Section 5: Networks and web technologies > Flashcards

Section 5: Networks and web technologies Flashcards

1
Q

What is the internet?

A

The internet is a network of inter-connected networks that communicate with each other globally.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the World Wide Web?

A

The World Wide Web is a collection of web pages that reside on computers connected to the internet.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is the internet physically structured?

A

Each continent uses backbone cables connected by trans-continental leased lines fed across the sea beds. National ISPs connect directly to this backbone and distribute the internet connection to smaller providers who in turn provide a connection for homes and businesses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a Uniform Resource Locator (URL)?

A

A URL is the full address of an internet resource, specifying the location of a resource on the internet including the resource’s name and file type so that a browser can request it from the website server.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a URL broken down into?

A

A URL is broken down into:

  • Method/protocol e.g. http
  • Domain name e.g. bbc.co.uk
  • Resource to be located e.g. index.html
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are internet registrars?

A

Internet registrars holds records of all existing website names and the details of those domains that are readily available to purchase. An example is 1and1.com

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are internet registries?

A

Internet registries are the five global organisations, governed by ICANN, with worldwide databases that hold records of all the domain names currently issued to individuals and companies, and their details. They also allocated IP addresses and keep track of which addresses and domain names are associated as part of the DNS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does ICANN stand for?

A

ICANN: Internet Corporation for Assigned Names and Numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does DNS stand for?

A

DNS: Domain Name System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the hierarchy of domains via. the DNS?

A

Domain hierarchy:

  • Top level domain (TLD) split into generic TLDs (e.g. ‘.com’) and country TLDs (e.g. ‘.uk’)
  • 2nd level domain (2LD) e.g. ‘.co’
  • 3rd level domain (3LD) e.g. ‘.bbc’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the DNS do?

A

The DNS catalogues all domain names and IP addresses in a series of global directories that domain name servers can access in order to find the correct IP address location for a resource.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the difference between a domain name and a fully qualified domain name?

A

A fully qualified domain name includes the host server name (e.g. “www.”, “mail.”), whereas a domain name on its own does not.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does an IP address indicate?

A

An IP address indicates where a packet is to be sent to, or from whence it came.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a Wide Area Network (WAN)?

A

A WAN is a network that relies on third-party carriers or connections, such as those provided by BT. WANs usually spread over a large geographical area.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a Local Area Network (LAN)?

A

A LAN is a network that consists of a number of devices on a single site, or in a single building.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the structure of a bus topology.

A

In a bus topology, all computers are connected to a single cable, with the ends of the cable plugged into a terminator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the main advantage of a bus topology?

A

The main advantage of a bus topology is that it is very cheap to install since it only requires very little cabling and it does not require any additional hardware.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the disadvantages of a bus topology? (3)

A

Disadvantages of a bus topology:

  • If the main cable breaks, none of the nodes can transmit data across the network
  • Performance degrades with heavy traffic
  • Low security since all the computers on the network can see the data transmissions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the structure of a star topology.

A

A star topology has a central node, which could be a switch or a computer, which acts as a router to transmit messages. The switch keeps a record of each node’s MAC address so it knows which computer to send data to.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the advantages of a star topology? (5)

A

Advantages of a star topology:

  • If one cable fails, only one station is affected so it is easy to isolate faults
  • Has consistent performance even if it is being heavily used
  • Higher transmission speeds can give better performance than a bus network
  • No data collisions since each station has its own cable to the switch
  • Easy to add and update stations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the disadvantages of a star topology? (2)

A

Disadvantages of a star topology:

  • May be costly to install due to cabling costs
  • If the central switch goes down, data cannot be transmitted to any of the nodes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the physical topology of a network?

A

The physical topology of a network is its actual design layout i.e. how the wiring is structured.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the logical topology of a network?

A

The logical topology of a network is the shape of the path that the data travels in, and describes how components communicate across the physical topology.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is Wi-fi?

A

Wi-fi is a local area wireless technology that enables you to connect a device to a network resource or the internet via a Wireless Access Point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe a mesh topology.

A

In a mesh topology, each node has a wireless connection to every other node, by transmitting data across any intermediate nodes. Only one node requires an internet connection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the advantages of a mesh topology? (4)

A

Advantages of a mesh topology:

  • No cabling costs
  • The more nodes installed, the faster and more reliable the network is since there are more paths for data to travel through
  • New nodes are automatically incorporated into the network
  • Faster communication since data packets do not need to travel through a central switch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is circuit switching?

A

Circuit switching is the formation of a direct link between two devices for the duration of their communication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is an example of circuit switching?

A

An example of circuit switching would be a phone call, as the two callers stay connected even in periods when no sound is being transmitted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is packet switching?

A

Packet switching is a method of communicating packets of data across a network on which other similar communications are happening simultaneously. For example, website data that you receive arrives as a series of packets and an email will leave you in a series of packets.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a packet?

A

A packet is a collection of data that enables computers to communicate with each other across a network.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the general size range of a packet?

A

A packet usually holds 500-1500 bytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the header of a packet contain?

A

The header of a packet includes the sender and recipient’s IP addresses, the protocol being used, the number of the packet in the sequence (e.g. 3/8) and the Time To Live/hop limit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does the payload of a packet contain?

A

The payload of a packet contains the actual data that is being sent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are routers used for?

A

Routers are used to connect two or more networks, commonly LANs and WANs, or to connect a LAN and its ISP’s network. They read the recipient’s IP address and forward the packet along the least congested route towards its destination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is a hop?

A

A hop is the act of traversing between one router and another across a network.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is a routing table?

A

A routing table is a table used by routers that allows them to store and update the locations of other network devices and the most efficient routes to them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a MAC address?

A

A MAC address is an address that is unique to every Network Interface Card (NIC) and therefore to every device which is capable of being part of a network.

38
Q

How is a MAC address formatted?

A

A MAC address is 48 bits, split into 12 hex digits, e.g:

28-16-A8-56-93-BF

39
Q

What is a protocol?

A

A protocol is a set of rules defining common methods of data communication.

40
Q

What is the Transmission Control Protocol/Internet Protocol (TCP/IP) stack?

A

The TCP/IP stack is a set of networking protocols that work together as four connected layers, passing incoming and outgoing data packets up and down the layers during network communication.

41
Q

What are the four layers in the TCP/IP stack from the top down?

A

Four layers in the TCP/IP stack:

  • Application layer
  • Transport layer
  • Internet layer
  • Link layer
42
Q

What happens at the application layer?

A

The application layer uses protocols relating to the application that is being used to transmit data over a network (usually the Internet). E.g. for a browser it would select a suitable protocol such as HTTP, POP3 or FTP.

43
Q

What happens at the transport layer?

A

The transport layer uses the Transmission Control Protocol (TCP) to establish an end-to-end connection with the recipient computer. The data is then split into packets and labelled with the packet number, the total number of packets and the port number to ensure it is handled by the correct application on the recipient computer.

44
Q

What happens at the internet layer?

A

The internet layer adds the source and destination IP addresses to forward the packets on to their destination. This forms a socket which is used to specify which device the packet must be sent to and the application to be used on that device.

45
Q

What is a socket?

A

A socket is the composition of an IP address and a port, for example:
“88.98.32.107:80”

46
Q

What happens at the link layer?

A

The link layer is the physical connection between network nodes and adds the MAC addresses of the source and destination so that the packets can find the correct piece of hardware once they have found the network.

47
Q

What is File Transfer Protocol (FTP)?

A

FTP is a high level protocol in the application layer which is used to transfer files across the internet. The user is presented with a file management screen showing the file and folder structure in both the local computer and the remote website.

48
Q

What is a good example of a use of FTP?

A

An example of a use of FTP is a software company offering large updates.

49
Q

What is Post Office Protocol v3 (POP3)?

A

POP3 is an email protocol responsible for retrieving emails from a mail server that temporarily stores your incoming mail. When an email is retrieved, it is transferred to the device it is being received on and then deleted from the mail server.

50
Q

What is Internet Message Access Protocol (IMAP)?

A

IMAP is an email protocol responsible for receiving emails, keeping the emails stored on the mail server and thus maintaining synchronicity between devices using the same mail server.

51
Q

What is Simple Mail Transfer Protocol (SMTP)?

A

SMTP is an email protocol used to transfer outgoing emails from one server to another or from an email client to the server.

52
Q

What is a firewall?

A

A firewall is a security checkpoint designed to prevent unauthorised access between two networks.

53
Q

How would a firewall be physically structured?

A

The typical firewall contains two NICs, with one connected to the internal network and one connected to the external network.

54
Q

What is packet filtering?

A

Packet filtering controls network access according to network administrator rules and policies by examining the source and destination IP addresses in the packet headers.

55
Q

What does a proxy server do?

A

A proxy server intercepts all packets entering and leaving a network, hiding the true network addresses of the source from the recipient. It can also maintain a cache of commonly visited websites so that the page data can be immediately returned to the user.

56
Q

What are proxy servers often used for?

A

Proxy server are often used to filter requests providing administrative control over the content that users may demand, e.g. a school network that filters undesirable online content in accordance with the school usage policies.

57
Q

What do viruses and worms have in common?

A

Both viruses and worms have the ability to self-replicate by spreading copies of themselves.

58
Q

What is the distinction between viruses and worms?

A

Viruses reside in a host file and rely on the user to open them, whereas worms do not need any user intervention and can spread themselves by attacked vulnerabilities in the network/system.

59
Q

What is a Trojan malware?

A

A Trojan is a piece of malware that seems legitimate, however in reality it has malicious content.

60
Q

What is tuffer overflow?

A

Tuffer overflow occurs when a program writes values to memory locations that are too small to handle them, and inadvertently overwrites the values in neighbouring locations that it is not supposed to have access to. As a result, the data is often interpreted as instructions.

61
Q

What are the most effective ways to protect against social engineering?

A

The most effective ways to protect against social engineering are spam filtering and education in being skeptical and cautious.

62
Q

What is HyperText Markup Language (HTML)?

A

HTML is the language or script that web pages are written in, describing the content and structure of a web page so that a browser is able to interpret and render the page for the viewer.

63
Q

What does the <div> tag in HTML do?</div>

A

In HTML, the <div> tag divides the page into separate areas, each of which can be referred to or styled differently.</div>

64
Q

What is the purpose of web forms?

A

The purpose of web forms is to enable websites to collect user input data and selections.

65
Q

Why is JavaScript interpreted rather than compiled?

A

Compilers produce object code which is specific to a particular type of processor. JavaScript, however, needs to be translated into object code for the browser that it is running on and is therefore translated by the interpreter when the page is displayed.

66
Q

What is ‘Just-In-Time’ compilation?

A

‘Just-In-Time’ compilation is a method of compilation used by new browsers which compiles JavaScript into executable bytecode just before execution.

67
Q

What is a search engine?

A

A search engine is a system that locates resources on the internet.

68
Q

What is search engine indexing?

A

Search engine indexing is the process of sending out a software program called a web crawler that finds all pages currently on the index and fetches all the sites that are linked to by those sites until they have linked to as many resources as possible.

69
Q

What is a meta tag?

A

A meta tag is a list of keywords and concise phrases specified by the website owner that are built into each webpage.

70
Q

How does Google’s PageRank algorithm work?

A

Google’s PageRank algorithm works by ranking web pages based on how many of the visits to that site have come from it being linked to another site. The algorithm also takes into account the reputation of the site e.g. a .gov website would be considered very reliable.

71
Q

How is a client-server network structured?

A

In a client-server network, one or more computers (known as clients) are connected to a powerful central computer known as the server. Each client may hold some of its own files and resources such as software, and can also access resources held by the server.

72
Q

What does a file server do?

A

A file server holds and manages data for all clients.

73
Q

What does a print server do?

A

A print server manages print requests.

74
Q

What does a web server do?

A

A web server manages requests to access the Web.

75
Q

What does a mail server do?

A

A mail server manages the email system.

76
Q

What does a database server do?

A

A database server manages database application.

77
Q

What are the advantages of a client-server network?

A

Advantages of a client-server network:

  • Better security as all files are stored in a central location and access rights are managed by the server
  • Backups are performed centrally so don’t need to be done on an individual basis
  • Data and other resources can be shared
78
Q

What are the disadvantages of a client-server network?

A

Disadvantages of a client-server network:

  • Expensive to install and manage
  • Professional IT staff are needed to maintain and run the network
79
Q

What is Cloud computing?

A

Cloud computing is a service-based industry which provides access to software or files via the internet using a client-server model. Companies will provide remote storage facilities for users to store their files and software on.

80
Q

How is a peer-to-peer network structured?

A

In a peer-to-peer network, there is no central server - individual computers are connected to each other, either locally or over a WAN so that they can share files.

81
Q

What are the advantages of a peer-to-peer network in a small LAN?

A

Advantages of peer-to-peer for a small LAN:

  • Cheap to set up
  • Enables users to share resources such as a printer or router
  • Not difficult to maintain
82
Q

How can peer-to-peer networks be used for piracy?

A

Using a peer-to-peer network, the load of thousands of people downloading films can be shared across hundreds of computers. This makes it impossible to trace the files which are being illegally downloaded.

83
Q

What is client-side processing?

A

Client-side processing describes situations where data is processed on the client computer, rather than on the server. This may happen because the client computer has specific software that can process the information, or to lighten the load on the server’s processor. Client-side processing can also improve security as it can avoid unnecessary data transfer.

84
Q

What is server-side processing?

A

Server-side processing is when servers process an enormous volume of data on behalf of multiple clients. Servers can process the data much faster than a client computer. Validation may also be carried out on the server where an invalid entry must be compared with data already on a server database.

85
Q

What is an Application Programming Interface (API)?

A

An API is a set of protocols that governs how two applications should interact with one another. It sets out the format of requests and responses between a client and a server and enables one application to make use of the services of another. E.g. an travel booker may use a Google Maps API to display an interactive window with the location of a hotel on.

86
Q

What does the “thickness” of a client computer refer to?

A

The thickness of a client computer refers to the level of processing and storage that it does compared with the server it is connected to. The more processing and storage that a server does, the “thinner” the client becomes.

87
Q

What are the advantages of thin-client computing?

A

Advantages of thin-client computing:

  • Easy to set up, maintain and add terminals to a network with little installation required locally
  • Software and updates can be installed on the server and automatically distributed to each client terminal
  • More secure since data is all kept centrally in one place
88
Q

What are the disadvantages of thin-client computing?

A

Disadvantages of thin-client computing:

  • Reliant on the server, so the terminals will go down if the server does
  • Requires a very powerful and reliable server (expensive)
  • Server demand and bandwidth increased
  • Maintaining network connections for portable devices consumes more battery power than local data processing
89
Q

What are the advantages of thick-client computing?

A

Advantages of thick-client computing:

  • Robust and reliable, providing greater up-time
  • Can operate without a continuous connection to the server
  • Generally better for running more powerful software applications
90
Q

What are the disadvantages of thick-client computing?

A

Disadvantages of thick-client computing:

  • More expensive, higher specification client computers required
  • Installation of software required on each terminal separately and network administration time is increased
  • Integrity issues with distributed data

A-Level Computing (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions