Section 10: The Internet Flashcards
1
Q
Chapter 56:
What is an example of where the Internet is used without the World Wide Web?
A
Online Games,
Messaging platforms,
Smartphone apps.
2
Q
Chapter 56:
What is the Physical Structure of the Internet?
A
Continents all have a Backbone that is joined by trans-continental leased lines across the sea bed.
National Internet Service Providers (ISPs) connect directly to the backbone and distribute the connection to smaller ISPs.
These smaller ISPs provide access to individuals’ homes and businesses.
3
Q
Chapter 56:
What does URL stand for?
A
Uniform Resource Locator.
4
Q
Chapter 56:
What does a URL do?
A
It is a full address for an Internet Resource.
It specifies the location of a resource, including the name and usually the file type, so that a browser can request it from the website server.
5
Q
Chapter 56:
The URL has 4 main components.
What are they?
A
Method / Protocol.
Host.
Location.
Resource.
6
Q
Chapter 56:
What are the different levels to the internet called?
[Who owns IP addresses, who distributes, who uses?]
A
Internet Registry,
Internet Registrar,
Internet Registrant.
7
Q
Chapter 56:
What is an Internet Registry?
A
They control the allocations of IP addresses and domain names.
They allocate to ISPs.
8
Q
Chapter 56:
What is an Internet Registrar?
A
Internet Service Providers (ISPs).
Businesses that sell IP addresses and domain names to customers.
9
Q
Chapter 56:
What is an Internet Registrant?
A
A person, or company that registers a domain name.
10
Q
Chapter 56:
What are the 5 Internet Registries?
Who are they all governed by?
A
All governed by [ICANN]
The Internet Corporation for Assigned Names and Numbers.
ARIN, LACNIC, RIPE NCC, AFRINIC, APNIC.
[ARIN]
American Registry for Internet Numbers (North America).
[LACNIC]
Latin America and Caribbean Network Information Centre (South America).
[RIPE NCC]
Réseaux IP Européens Network Coordination Centre (Europe, Greenland, and all of Russia).
{Réseaux = “Network”} {Européens = “Europeans”}.
[AFRINIC]
African Network Information Centre (Africa).
[APNIC]
Asia Pacific Network Information Centre (Asia and Oceania).
11
Q
Chapter 56:
What does DNS stand for?
A
Domain Name System.
12
Q
Chapter 56:
What does a Domain Name do?
A
A Domain Name is the area (or domain) that an Internet resource resides in.
Domain Names are structured in a hierarchy that is known as a Domain Name System (DNS).
Each Domain Name has one or more equivalent IP addresses.
13
Q
Chapter 56:
Why are IP Addresses not used instead of alphanumeric characters?
A
Because alphanumeric characters are easier to remember, and often more intuitive to humans.
14
Q
Chapter 56:
What does TLD stand for?
A
Top Level Domain.
15
Q
Chapter 56:
What does FQDN stand for?
What is it?
A
Fully Qualified Domain Name.
A Domain Name that includes the host server name.
For example www, mail, or ftp.
16
Q
Chapter 56:
What does IP in IP Address stand for?
A
Internet Protocol.
17
Q
Chapter 56:
What does an IP Address do?
A
Unique address that is assigned to one network device at a time.
The IP Address indicates where a packet of data is to be sent to, or has been sent from.
Routers use the IP Address to direct the data packet accordingly.
18
Q
Chapter 57:
What is Packet Switching?
A
A method of communicating packets of data across a network.
Different packets are sent down different wires to reduce congestion, and so that they all reach the target in a smaller amount of time.
19
Q
Chapter 57:
What is a Data Packet?
A
A manageable chunk of data that has been broken down for transmission across a network.
20
Q
Chapter 57:
Data Packets are split into 2, or sometimes 3 parts.
What are these parts called?
A
Header.
Payload.
Trailer. (not always used)
21
Q
Chapter 57:
What does the Header of a Data Packet do?
A
Contains the sender’s and the recipient’s IP Addresses,
the protocol used for the packet,
and the index of the transmission that the packet represents. (e.g. package 3 of 8).
They also include a Time To Live (TTL) or hop limit, after which point the data packet expires and is discarded.
22
Q
Chapter 57:
Why is the sender’s IP Address sent with packets?
A
To Identify the sender.
This is used to send a reply to the same IP Address.
This allows the Network to send an error message back to the sender.
This is also used in firewalls, and IP Address filtering.
23
Q
Chapter 57:
What does the Payload of a Data Packet do?
A
The Payload is the actual data being sent.
The Header and Trailer are more like metadata.
24
Q
Chapter 57:
What does the Trailer of a Data Packet do?
A
Contains a checksum or Cyclical Redundancy Check (CRC).
This is used for Error Checking.
25
Chapter 57:
| What route is taken by Data Packets through a network?
A path of lowest transmission time is calculated for every packet.
That path is used.
26
Chapter 57:
| How are Data Packets reassembled by the recipient?
Each packet stores an ordinal number that represents its position in the full transmission.
Each packet also stores the total number of packets, so the receiver can work out if it has all of the packets or not. (If not, it can send a request for the packets that didn't arrive).
27
Chapter 57:
| What do Routers do?
Connect 2 or more networks together.
Typically LANs and WANs, or LANs to their ISP's network.
They take packets, read their destination, find the shortest path to the destination, and send it in that direction.
28
Chapter 57:
| What is a common shortest path algorithm?
Dijkstra's Algorithm.
29
Chapter 57:
| Why does the IP Address of a router need to be registered with the Internet Registry?
Because the IP Address must be unique across the whole Internet.
30
Chapter 57:
| What is a Gateway?
Also known as a Protocol Converter.
Used to connect devices that use different protocols to operate (converts the protocol).
31
Chapter 57:
| What is the difference between a Router and a Gateway?
Router connects two devices to Route Traffic of the same protocol.
Using Dynamic Routing, Routers are usually faster.
Gateways also connect two devices to Route Traffic, but can convert to different protocols, so are more versatile.
Using Static Routing, Gateways are usually Slower.
32
Chapter 58:
| What is a firewall?
A security checkpoint designed to prevent unauthorised access between two networks, usually an internal, trusted network with an external, untrusted network (e.g. the Internet).
33
Chapter 58:
| Is a firewall Hardware, or Software?
Can be either.
Hardware: A device that links networks.
Software: Installed on all devices.
34
Chapter 58:
| What is the process of a firewall?
Packets attempt to pass.
Firewall checks the packet against preconfigured rules (packet filters).
Packet is either accepted or rejected.
Firewalls can also act as proxy servers.
35
Chapter 58:
| What is Packet Filtering?
Also known as Static Filtering.
Controls network access according to network administrator rules and policies.
This is done by looking at the source and destination IP Addresses in the header of a packet.
If IP Addresses match those recorded on the administrator's 'permitted' list, they are accepted.
Packet Filtering can also block packets based on the protocols being used, and the port numbers (location) they're trying to access.
36
Chapter 58:
| What is the difference between a Dropped Packet and a Rejected Packet?
Dropped Packets are quietly removed, whereas Rejected Packets will cause a rejection notice to be sent back to the sender.
37
Chapter 58:
| What is Stateful Inspection?
Also known as Dynamic Filtering.
The payload of a Packet is also checked for better safety.
It can also create temporary contextual rules based on previous packets in the 'conversation'.
38
Chapter 58:
| What structure does Stateful Inspection use to store temporary rules?
Connection Table.
39
Chapter 58:
| What is an example of Stateful Inspection?
When a Browser requests a web page, the web page packets are returned, and allowed through the Dynamic Filter.
40
Chapter 58:
| What does a Proxy Server do?
Interprets all packets entering and leaving a network, hiding the true network addresses of the source from the recipient.
This allows for privacy and anonymous surfing.
41
Chapter 58:
Proxy Servers have a Cache Store.
What is this used for?
When a Proxy server receives a request, it will check its cache for web data.
If the data is not present, the server will send a request to the web server.
The web data is then stored to cache before being transmitted to the client, so that other users can access that data quicker, while also reducing web traffic.
This also allows some web data to be accessed without access to the web server.
42
Chapter 58:
| What is an example of a Proxy Server?
School Web-Proxy Server.
Clients send a request to the School Web-Proxy.
The School Web-Proxy can assess if that data is appropriate, and provide or reject the page.
43
Chapter 58:
| What is the idea of Encryption?
Turning valuable data (plaintext) into a form that is not understood without a key (ciphertext).
The process of encryption is carried out using a cryptographic algorithm and a key.
44
Chapter 58:
| What is Symmetric Encryption?
The same key is used to Encrypt and Decrypt data. This means that the key must be transmitted as well (called key exchange), which can cause security issues.
45
Chapter 58:
| What is a disadvantage of Symmetric Encryption?
The Cipher key must be exchanged, usually through transmission like the ciphertext. This means that interceptions of both can be taken, and the security can fail.
46
Chapter 58:
| What is Asymmetric Encryption?
Two separate, but related keys are used in the Encryption.
47
Chapter 58:
| What are the two Asymmetric Encryption Keys called?
```
Public Key (Available to anyone).
Private Key (Available to user only).
```
48
Chapter 58:
| What is the process of Asymmetric Encryption?
The sender of data acquires the Public Key of the intended receiver to Encrypt data and send it off.
The receiver uses their own Private Key to Decrypt the data, as the two keys are mathematically related.
49
Chapter 58:
| Why is it so hard to derive the Private Key from the Public Key?
Private Keys are very large random numbers.
Public Keys are points on an Elliptic Curve, generated by using the Private Key as a Scalar.
Security is derived from the Discrete Log Problem;
Given a starting value and an ending value, it is difficult to derive the Scalar.
50
Chapter 58:
Governments sometimes demand copies of Encryption Keys in order to Decrypt messages if necessary.
What are reasons for and against this?
For:
Help track down criminals.
Help prevent crime.
Against:
Personal Privacy.
Potential to leak secret business projects.
51
Chapter 58:
| What is a Digital Signature?
An attachment to a file that confirms that the sender is who they say they are. It also prevents external parties from changing the data, as it will be detected.
52
Chapter 58:
| What is the process of using a Digital Signature?
Mathematical Value is calculated from the data to send. (Hash Value / checksum / digest).
Hash Value is Encrypted by the sender using their private key. (Digital Signature) [only the real user could create it, unless their private key has been breached].
Digital Signature is attached to the message.
Message (with Digital Signature) is Encrypted using the receiver's public key. (Ciphertext)
Ciphertext is transmitted.
Ciphertext is received.
Ciphertext is Decrypted by the receiver using their private key.
Receiver Decrypts the Digital Signature using the sender's public key. At the same time, the receiver calculates the Hash Value of the message without the Digital Signature.
If the receiver's Hash Value is equal to the sender's Hash Value, the Hash Value has been taken of the same data, thus the data is official.
53
Chapter 58:
| How can Digital Signatures help against viruses?
If the sender is trustworthy, you know you can use Digital Signatures, as the unchanged data is sent from a good source.
If the sender is trustworthy, but doesn't use a Digital Signature, that can mislead people into downloading data that has been changed by an untrustworthy source.
This can also damage the reputation of the trustworthy source, leaving users with less reputable senders.
If the sender is untrustworthy, and they use a Digital Signature, they can be exposed as untrustworthy, as their data is marked with their name.
54
Chapter 58:
| What is a Digital Certificate?
Issued by official Certificate Authorities (CAs) such as Symantec or Verisign.
Verifies the trustworthiness of a message sender or website.
The Certificate allows the holder to use the Public Key Infrastructure (PKI).
55
Chapter 58:
| What does a Digital Certificate have on it?
```
The certificate's serial number,
The expiry date,
The name of the holder,
A copy of the holder's public key,
A digital Signature of the Certificate Authorities.
```
56
Chapter 58:
| What layer of TCP/IP does the Digital Certificate operate?
The Transport Layer.
Using Transport Layer Security (TLS).
Which is beginning to supersede Secure Sockets Layer (SSL).
57
Chapter 58:
What is malware short for?
What are the 3 main types?
Malicious Software.
Worms,
Trojans,
Viruses.
58
Chapter 58:
| What is the purpose of Malware?
To cause inconvenience users.
To damage programs, data, or computer systems.
To exploit vulnerabilities in our systems, be they human error or software bugs.
59
Chapter 58:
What do Viruses and Worms have in common?
What makes them different?
They both have that ability to self-replicate by spreading copies of themselves.
A Worm is a subclass of virus, but the difference is that Viruses rely on host files (usually executable programs), whereas Worms do not.
60
Chapter 58:
| What happens when a file is loaded into memory, when there is a virus in the memory?
The file becomes infected.
61
Chapter 58:
| How are Worms harmful to a computer?
The Worm creates copies of itself, and spreads them.
This can be especially harmful as it can use up bandwidth, system memory, or network resources, causing a computers to slow and servers to stop.
62
Chapter 58:
| What are some Examples of Worms?
ILOVEYOU - Overwrites many file types and emails contacts with the same file(that spreads if opened).
Blaster - Infects and disables all .exe files on the computer
63
Chapter 58:
| What are some Examples of Viruses?
Melissa - Opening the .doc file will show a list of URLs for pornography sites. Once this is opened, the file will be copied and sent to contacts through email. Also, on trying to close any doc file, a Simpsons quote will be inserted into the bottom, before prompting the user to save.
Cascade - One of the more creative viruses; causes text to drop to the bottom of the screen in a pile.
64
Chapter 58:
| *What is the story of the Trojan Horse?
A royal from Troy fell in love with a Greek leader's wife. The Wife joined the Trojan royal and the Greek leader wasn't too happy about this.
The Greek leader joined with other Greek leaders and invaded Troy. The War lasted 10 Years, and the Greeks were never able to get over the walls to Troy.
One day, a Greek official had an idea to create a large wooden horse (horses being the emblem of Troy). The horse would be given to Troy as a surrender gift.
Troy accepted the gift noticing that all of the Greek ships had set sale over the horizon. The wooden horse was dragged into the city, and the citizens partied.
At night, a trapdoor opened in the horse and several Greek soldiers jumped out. One lit a torch and waved it to alert the ships (that were resting on the horizon) to come back. The rest of the soldiers opened the main gate.
The Greeks burned Troy to the ground, taking back the Greek leader's wife.
65
Chapter 58:
A Trojan is a type of computer malware.
What makes it different?
Its operation of a Trojan is very similar to that of the Trojan Horse story. (Hence the name).
The malware is hidden in what appears to be a useful file, game, or utility.
When installed onto your computer, the payload is released; it will open a back door to your computer system that the creator of the Trojan can exploit.
These types of malware are used to harvest personal information, or use your computer's power and bandwidth to send thousands of spam emails.
66
Chapter 58:
| What is an example of Human Error that can lead to System Vulnerability?
Disabling a firewall.
Failing to renew virus protection software.
Opening links from untrustworthy emails.
67
Chapter 58:
Buffer overflow is an example of a System Vulnerability.
What is it?
Why is it dangerous?
Buffer overflow occurs when data that is too large for a memory location is set to the location. This can cause the extra bits to push over into adjacent memory locations.
Attackers can abuse this by accessing bits that shouldn't be accessible.
68
Chapter 58:
What is Social Engineering?
What is an example?
Where people manipulate others into exposing them to malware.
Examples include Phishing and Pharming, as well as many more.
69
Chapter 58:
| What is Phishing?
Online contact (usually email), in which the attacker is disguised as a reputable source as to trick people into giving them personal information.
70
Chapter 58:
| What is Pharming?
A fake website, disguised as a real one, used to find out people's passwords, so that they can access their accounts.
71
Chapter 59:
| What does TCP/IP stand for?
Transmission Control Protocol / Internet Protocol.
72
Chapter 59:
| What are the 4 layers of the TCP/IP model called?
Application Layer,
Transmission Layer,
Network Layer,
Link Layer.
73
Chapter 59:
| What does the Application Layer of the TCP/IP model do?
Takes the data to send, and passes it to the Transport Layer.
It does this using a protocol such as HTTP, or FTP.
74
Chapter 59:
| What does the Transport Layer of the TCP/IP model do?
The Transport Layer establishes an end-to-end connection with the recipient computer using the Transmission Control Protocol (TCP).
The Transport Layer also splits the data into packets, labelling each packet with a packet number and a port number. If a packet is not received, the Transport Layer will request the data again.
The packets are then sent to the Network Layer
75
Chapter 59:
| What does the Network Layer of the TCP/IP model do?
Also known as the IP Layer, or Internet Layer.
The Network Layer adds the IP addresses of the sender and the receiver to the packets.
The receiver IP Address and the port number forms a socket. e.g. 42.205.110.140:80 (80 is the port).
The Packets are then sent to the Link Layer.
76
Chapter 59:
| What does the Link Layer of the TCP/IP model do?
The Link Layer adds the Media Access Control (MAC) Addresses of the sender and receiver to the Packets.
77
Chapter 59:
| When TCP/IP Packets are received, what is the process to convert them back?
Link Layer: Strips the MAC Addresses from the packets.
Network Layer: Strips the IP Addresses from the packets.
Transport Layer: Uses the Port number to determine which application to pass the data to.
Application Layer: removes port numbers and reassembles data in the correct order.
78
Chapter 59:
| What does MAC Address stand for?
Media Access Control Address.
79
```
Chapter 59:
What ports do the following protocols use?
FTP
SSH
HTTP
HTTPS
```
FTP: (data) 20
FTP: (control instructions) 21
SSH: 22
HTTP: 80 and 8080
HTTPS: 443
80
Chapter 59:
| What does FTP stand for?
File Transfer Protocol.
81
Chapter 59:
| What is FTP?
A very efficient method used to transfer data across a network, often the Internet.
82
Chapter 59:
| In what level of the TCP/IP model does FTP operate?
The Application Layer.
83
Chapter 59:
| What is SSH short for?
Secure Shell.
84
Chapter 59:
| What does SSH do?
Allows for remote access and management of a computer.
Uses a Digital Signature and Encryption.
85
Chapter 59:
| What is the difference between Telnet and SSH?
Both allow users to remotely access and manage a their computer. SSH was released after Telnet as a replacement.
SSH uses Public Key Encryption with a digital signature, where as Telnet uses no Encryption.
86
Chapter 59:
| What is the purpose of a Mail Server?
To act as a Virtual Post Office for all incoming and outgoing emails.
87
Chapter 59:
| What are the main 3 Protocols that a Mail Server uses?
Post Office Protocol v3 (POP3)
Internet Message Access Protocol (IMAP)
Simple Mail Transfer Protocol (SMTP)
88
Chapter 59:
| What is the Mail Protocol used to send an email?
Simple Message Transfer Protocol (SMTP).
89
Chapter 59:
| What are the Mail Protocols used to receive an email?
Post Office Protocol (POP).
Internet Message Access Protocol (IMAP).
90
Chapter 59:
POP and IMAP are protocols used by a Mail Server to send get a message to a client.
What is the difference between them?
Post Office Protocol (POP) deletes its own copy after the mail is sent. This uses less storage, but only allows a user access to the mail on one device.
Internet Message Access Protocol (IMAP) keeps a store of the message, and only ever sends a copy to the user. This allows the user access to the mail on multiple devices; client and mail server are "synced".
[
Way to remember:
A real Post Office doesn't keep a copy of your packages or letters.
]
91
Chapter 59:
| What is the role of a Web Server?
Used to host websites, and handle client requests.
92
Chapter 59:
| What is the most common Protocol for a Web Server to use?
HTTP.
| Hypertext Transfer Protocol
93
Chapter 59:
| What are the most common Programming Languages for Websites?
HTML,
CSS,
JavaScript.
94
Chapter 59:
| What does HTML stand for?
Hypertext Markup Language.
95
Chapter 59:
| What does CSS stand for?
Cascading Style Sheets.
96
Chapter 59:
When a Browser receives a HTML file, it needs to break it down into tags.
What is the name of the format that it is put into?
Document Object Model (DOM).
97
Chapter 59:
When a Browser receives a CSS file, it needs to break it down into tags.
What is the name of the format that it is put into?
CSS Object Model (CSSOM).
CSS = Cascading Style Sheets.
98
Chapter 60:
| What are the 2 standards of IP Address?
IPv4,
| IPv6.
99
Chapter 60:
* When was IPv4 first introduced?
* How many combinations does it support?
1983.
4 Billion, or 4 * 10^(9).
100
Chapter 60:
* When was IPv6 first introduced?
* How many combinations does it support?
* What makes it support more than IPv4?
1999.
3.4 * 10^(38) .
Represented with Hexadecimal, not Binary.
101
Chapter 60:
What is Dot-Decimal Notation?
Write 0xFF000000 in Dot-Decimal Notation.
A way of representing a number.
The number is written in denary(decimal), where numbers are separated by a dot.
[ 0x{} = Hex ]
255.0.0.0
102
Chapter 60:
| What form is IPv4 written in?
Dot-Decimal Notation.
32 Bits - separated into 4 Bytes.
(Split into groups of 8 bits)
103
Chapter 60:
The IP Address is made of two parts.
What are the two parts called?
Network ID (first part).
Host ID (second part).
104
Chapter 60:
| What is the idea of Classful Addressing?
(Not used anymore).
A system of classes is used to identify how much of the IP Address is the Network ID, and how much is the Host ID.
105
Chapter 60:
| What is the idea of Classless Addressing?
(Modern; used more often).
The IP Address has a component that indicates how much of the IP Address is the Network ID, the rest is the Host ID.
106
Chapter 60:
In the context of Classless Addressing, what can we say about the following IP Address?
103.27.104.92/24
We can say that the first 24 bits of the IP Address is the Network ID. (from "/24").
We can see that it is displayed in Dot-Decimal Notation, and therefore say that (as 4 bytes are used), 32 bits are available.
Using this, we can say that the last 8 bits (32-24) represent the Host ID.
107
Chapter 60:
| What is a Subnet Mask?
Used to identify which parts of the IP Address is the Network ID. (And, in turn, the Host ID).
108
Chapter 60:
How is a Subnet Mask related to Classless Addressing form?
What is "/24" in Subnet Mask form?
The number after the slash of the Classless Addressing form is the number of bits that define the Network ID.
"/24" = First 24 bits are 1.
11111111.11111111.11111111.00000000
(Convert into dot decimal notation.)
255.255.255.0
109
Chapter 60:
| How does the computer get the Network ID from the IP Address?
IP Address BITWISE AND Subnet Mask.
110
Chapter 60:
| What is Subnetting?
Where the Host ID of an IP Address is split into a Subnet ID and a smaller Host ID.
The Subnet ID will take the more significant bits of the original Host ID.
This allows Clients in every subnet to communicate internally at the same time while also avoiding collisions.
111
Chapter 60:
| What is the difference between a Public and Private IP Address?
Pubic (Routable) IP Addresses must be globally unique, as anyone will be able to address them.
Private (Non-Routable) IP Addresses cannot be addressed directly from anywhere in the world, so only need to be locally unique.
112
Chapter 60:
| What can we use to access a Privately Addressed computer externally?
A Network Address Translator (NAT).
113
Chapter 60:
| What does DHCP stand for?
Dynamic Host Configuration Protocol.
114
Chapter 60:
| What is DHCP used for?
Dynamic IP Addressing.
Allowing devices to request an IP Address from a pool of available ones, and release it back when the device disconnects.
Also provides the Subnet Mask.
115
Chapter 60:
| What is a NAT?
Network Access Translation.
It allows a Private network and a Public network to communicate through the Router(which has a Public and Private IP Address).
116
Chapter 60:
| What is Port Forwarding?
Used when a Public IP Address needs to access a Private Server.
The Public IP Address will send data to the Router's Public Address with an attachment (port). The Router will then take the port number and search a preset table. If the port is defined, it will have a Private IP Address to send the packets to.
117
Chapter 61:
| What is the Client-Server Model?
Where a Client sends a data request to a server, and the server sends the data back.
An example of this is a Web Browser, where the Browser sends a request to a Web Server, and the Web Server will send back the Web Page data.
118
Chapter 61:
| What does API stand for?
Application Programming Interface.
119
Chapter 61:
| What does an API do?
Governs how two applications should interact with each other.
120
Chapter 61:
| What is the WebSocket Protocol?
A Modern API, used most often in Web Servers.
WebSocket is Persistent(always open), bi-directional, fast, and real-time. Transmissions are also smaller due to smaller packet header sizes being required.
121
Chapter 61:
| What are the Advantages of an online Auction website using WebSocket Protocol?
Real-Time.
In order to place bids on an item, the buyer needs to be able to see the item, think about it, and send in an offer before the auctioneer has moved on.
Smaller Packet Sizes.
If an auction has 100+ bidders, communication needs to be quick, so that real-time communication can be achieved. This also puts less pressure on web servers.
Connection.
Bidders are less likely to disconnect, due to the persistent nature of WebSocket.
122
Chapter 61:
| What does CRUD stand for?
Create, Retrieve, Update, Delete.
123
Chapter 61:
| What is CRUD?
Create, Retrieve, Update, Delete.
The four fundamental operations of a Database.
Has equivalents in SQL and HTTP.
SQL: INSERT, SELECT, UPDATE, DELETE.
HTTP: POST GET PUT DELETE.
124
Chapter 61:
| What does REST stand for?
Representational State Transfer.
125
Chapter 61:
| What does REST do?
REST is an Architectural style. HTTP is an example of what uses this style.
It allows a Web Server to interact with a Database Server.
126
Chapter 61:
| What is JSON short for?
JavaScript Object Notation.
127
Chapter 61:
| What is XML short for?
EXtensible Markup Language.
128
Chapter 61:
| What are the advantages to using JSON over XML?
Easier to read.
More compact.
Easier to create.
Easier/Quicker to pass.
129
Chapter 61:
| What are the advantages to using XML over JSON?
More Flexible.
130
Chapter 61:
| What does the thickness of a Client refer to?
The Level of Processing and Storage that the Client has in comparison to the Server.
The Smaller the Client is * the thinner the Client operates as.
*(in terms of Processing and Storage),
131
Chapter 61:
| What are the advantages of Thin-Client Computing?
Easy to setup and maintain.
Updates can be installed to the server and will be active for all users.
More Secure, as data is stored in one place.
132
Chapter 61:
| What are the disadvantages of Thin-Client Computing?
Reliant on the server; if the server goes down, functionality is lost for all users.
Server requirements (Processing, Power, Bandwidth) are very high, and will therefore be very expensive.
133
Chapter 61:
| What are the advantages of Thick-Client Computing?
Robust, and reliable; greater up-time.
Can operate without continuous connection to the server.
Generally better for running more powerful software applications.
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Chapter 61:
| What are the disadvantages of Thick-Client Computing?
Client Computers are more expensive; (external: less accessible) (internal: less viable).
Installation of software on each device is required.
Integrity issues with distributed data.
