Year 13 Theory Test 1 Flashcards
1
Q
What are the features of Serial Files?
A
- Data is stored in the order in which it is entered.
- No order to the data is maintained.
- Useful for storing transactional data and initialisation files.
2
Q
What are the features of Sequential Files?
A
- Store data in order of a key field.
- The order is maintained when new records are added.
- Useful for storing master files.
3
Q
What is a Database?
A
A structured, persistent collection of data.
4
Q
What are the advantages of Databases?
A
- Makes processing more efficient.
- Reduces storage requirements.
- Avoids redundancy.
- Allows different users to only see relevant data.
5
Q
What does DBMS Stand for?
A
DataBase Management System
6
Q
What is a DataBase Management System?
A
A software system that enables the definition, creation and maintenance of a database and which provides controlled access to this database.
7
Q
What is a Table?
A
A collection of related data and is made up of Records and Fields.
8
Q
What is a Field?
A
Used in a database to provide category headings for each item of data in the database.
9
Q
What is a Record?
A
A collection of data for one object, person, or thing.
10
Q
What is a Primary Key?
A
An attribute or set of attributes which uniqely identifies a tuple.
11
Q
What is a Composite Key?
A
A combination of attributes that uniquely identifies a tuple/ record.
12
Q
What is a Foreign Key?
A
An attribute in one table that is a primary key in another table.
13
Q
What is a Data Model?
A
An abstract model for organising data and its relationship in real world entities.
14
Q
What is Entity-Relationship Modelling?
A
A method of abstractly describing the data tables and the relationships between them visually. They can be used to reduce redundancy and construct a relational database.
15
Q
What is an Attribute?
A
A characteristic specification that defines a property or feature about an entity stored in a database.
16
Q
What is a Relational Database?
A
A database where separate tables are made for each entity, and the relationships between entities are represented by foreign keys.
17
Q
What is Normalisation?
A
The formal process of optimally designing data tables by reducing data redundancy and repitition by converting them into normal forms.
18
Q
What is First Normal Form (1NF)?
A
A table with no repeating attributes. The intersection of each record and attribute produces exactly one value.
19
Q
What is Second Normal Form (2NF)?
A
A table in 1NF that has data that repeats across multiple records removed and put into a new table with appropriate relationships (no partial dependencies).
20
Q
What is Third Normal Form (3NF)?
A
A table in 2NF where all attribures that are not the primary key are fully dependent on the primary key, meaning there are no non-key dependencies.
21
Q
What does SQL stand for?
A
Structured Query Language
22
Q
What is SQL?
A
A language for relational database management and manipulation.
23
Q
What is a Client Server Database?
A
A system that provides simultaneous access to the database for multiple clients.
24
Q
What is a Router?
A
A device that receives packets from one host or router and uses the destination IP address that they contain to pass them correctly ormated to another host, or router.
25
What is a Gateway?
A device used to connect networks using different protocols so that information can be successfully passed from one system to another.
26
What is a Domain Name?
The name that locates a domain on the internet. It is included as part of a URL.
27
What does DNS stand for?
Domain Name Server
28
What is a Domain Name Server System?
A hierarchical and decentralised naming system for computer systems connected to the internet. It contains the IP addresses of all domain names on the internet.
29
What does FQDN stand for?
Fully Qualified Domain Name
30
What is a Fully Qualified Domain Name?
A domain name specifying the exact location of a domain in the Domain Name Server System hierarchy.
31
What is the Internet?
A global network of computer systems communicating using TCP/ IP.
32
What are Internet Registries?
Organisations responsible for the allocation of Domain Names and IP Addresses.
33
What does IP stand for?
Internet Protocol
34
What is an IP Address?
A numerical address assigned to any device communicating via Internet Protocol on a network that identifies its host and addresses its location.
35
What is a Packet?
A block of data.
36
What is Packet Switching?
A method for sending data over a network by breaking data into several data packets which are sent independently and then reassembled once they all reach their destination.
37
What is the Process of Packet Switching.
1. Data is split into equally-sized packets.
2. They are attached with a header for error checking.
3. They are given an IP address and then sent across the network.
4. Each packet generally takes different routes depending on the levels of traffic at each route.
5. The packets are checked for errors and the recipient requests the packet to be resent if there is an error.
6. The packets will usually be out of order when they arrive, so are put back into order when they all arrive.
38
What does URL stand for?
Uniform Resource Locator
39
What is a URL?
A reference to a resource on the internet that is able to locate and retrieve it.
40
What is a Firewall?
a security checkpoint application that monitors incoming and outgoing network traffic, designed to prevent exteranl users from gaining unauthorised access between two networks.
41
What is Asymmetric Encryption
An encryption tecnhique where a public key available to everyone is used to encrypt the data, and the data is decrypted by the paired private key known only by the recipient.
42
What is Symmetric Encryption?
An encryption technique where the same key is used to encrypt and decrypt data. A copy of the key must be transferred between both parties.
43
What is a Digital Certificate?
An electronic docmument providing ownership of a public key and hence authenticating your identity.
44
What is a Digital Signature?
A mathematical scheme for producing a unique signature, that verifies the authenticity of encrypted digital messages.
45
What is a Certification Authority?
A trusted organisation which is responsible for providing digital certificates,
46
What is the process of applying a Digital Signiture?
1. Apply a hash function to the plaintext message to produce a message digest.
2. Use the private key to encrypt the message digest. The encrypted digest becomes the digital signiture.
3. Attach the digital signature to the plaintext message and encrypt the whole thing with Public Key.
4, Decrypt with the recipient;s private key.
5. Extract the digital signature with the recipient's public key.
6. The message digest is regenerated by applying the hash function to the plaintext message.
7. Compare the regenerated message digest with the original digest.
47
What does Malware stand for?
Malicious Software
48
What is Malware?
A broad catch all term to describe any software which has been written with an intent to cause damage/ harm/ corruption/ nuisance.
49
What is a Trojan?
A malware that hides within another file and misleads the user of its true intnet.
50
What is a Virus?
A program that attaches itself to antoher computer file to infect a computer system by replicating itself and inserting its code into other files.
51
What is a Worm?
A standalone virus capable of spreading and infecting a computer without being attached to a file.
52
What is a Port?
A communication endpoint that addresses a service on a network. It is used to represent services or applications.
53
What is a Socket?
A softwar that serves as an endpoint for sending and receiving data cross a network.
54
What does TCP/IP Stand For
Transmission Control Protocol/ Internet Protocol
55
What is the TCP/IP Stack?
A suite of networking protocols that allow networked computers to communicate, consisting of 4 connected layers. Incoming and outgoing data packets are passed through these layers.
56
What is Layer 1 in the TCP/IP Stack?
Application Layer.
57
What is the Application Layer?
Used to provide services for applications that want to communicate across a networ, often the internet.
58
What is Layer 2 in the TCP/IP Stack?
Transport Layer
59
What is the Transport Layer?
Uses the Transmission Control Protocol to establish an end-to-end connection with the recipient computer.
60
What is Layer 3 in the TCP/IP Stack?
Network Layer
61
What is the Network Layer?
Uses the Internet Protocol to address packets with the source and destination IP addresses.
62
What is Layer 4 in the TCP/IP Stack?
Link Layer
63
What is the Link Layer?
Operates across a physical connection.
64
What happens in the Application Layer (Layer 1) of the TCP/IP Stack?
- Uses high-level protocols that set an agreed standard between the communicating end-points.
- Does not actually determine how the data is transmitted, rather specifies the rules of what should be sent.
65
What happens in the Transport Layer (Layer 2) of the TCP/IP Stack?
- Splits data into packets and numbers then sequentially.
- Adds the port number to be used based on HTTP protocol.
- At the receiving end this layer confirms that packets have been received and requests any missing packets to be resent.
66
What happens in the Network Layer (Layer 3) of the TCP/IP Stack?
- A router forwards each packet towards an endpoint called a sockt, defined by the combination of IP address and port number.
- Each router uses a routing table to instruct the next hop.
67
What happens in the Link layer (Layer 4) of the TCP/IP Stack?
- Adds the MAC address of hte physical NIC that packets should be sent to, based on the destination IP Address.
- MAC Addresses change with each hop.
68
What is an Email Server?
A computer system on a network designated to handle emails being sent and received by other computers on the network.
69
What does FTP stand for?
File Transfer Protocol
70
What is the File Transfer Protocol?
A protocol used for downloading or uploading files from a computer system.
71
What does HTTP stand for?
Hyper-Text Transfer Protocol
72
What is the HTTP protocol?
A protocol used to fetch, render and transmit webpages.
73
What does HTTPS stand for?
Hyper-Text Transfer Protocol Secure
74
What is the HTTPS protocol?
An encrypted version of HTTP.
75
What does POP3 Stand for?
Post Office Protocol Version 3
76
What is the POP3 Protocol?
An application-layer internet standard protocol used to receive emails from a server.
77
What is a Secure Shell?
An encrypted protocol that allows secure communication between nodes across a network.
78
What is Secure Shell Tunneling
SSH can be used to create a tunnel through a network. This tunnel can be used to pass through data that might otherwise be blocked.
79
What does SMTP Stand for?
Simple Mail Transfer Protocol
80
What is the SMTP Protocol?
An internet standard communication protocol for sending emails.
81
What des IMAP Stand for?
Internet Message Access Protocol
82
What is the IMAP Protocol?
Controls the download/ upload of emails to and from the mail server.
83
What is the Port Number for FTP?
20 - FTP DATA
21 - FTP CONTROL
84
What is the Port Number for Secure Shell?
22 - Secure Shell Remote Login
85
What is the Port Number for Telnet?
23 - Telnet (unencrypted) Remote Login.
86
What is the Port Number for HTTP?
80 or 8080 - HyperText Transfer Protocol
87
What is the Port Number for POP3?
110 - Post Office Protocol Version 3
88
What is the Port number for IMAP?
143 - Internet Mail Access Protocol
89
What is the Port Number for HTTPS?
443 - HyperText Transfer Protcol Secure
90
What is a Web Browser?
An application software used to view webpages a computer system has requested from a web server.
91
What is a Web Server?
A computer system on a network designated to handle web requests through HTTP(S).
92
What is a Host Identifier?
A series of bits that form part of hte IP Address that uniquely identify the computer on the network it is in.
93
What is a Network Identifier?
A series of bits that form part of hte IP address and identify the network the computer connected to the internet is on.
94
What is a Subnet?
A smallernetwork that forms a subset of a whole network.
95
What are the ranges of iPv4?
0.0.0.0 to 255.255.255.255
96
What do these IP Addresses represent?
- 10.x.y.z
- 172.16.0.1 to 172.31.255.255
- 192.168.y.z
Private, non-routable addresses used for LANs or Private WANs only.
97
What do these IP Addresses represent?
- x.y.z.0
The Whole Network.
98
What is the last address in a network reserved as?
The broadcast address on that network, for sending data simultaneously to all hosts on that network.
99
What do these IP Addresses Represent?
- 127.x.y.z
Reserved for loopback, in which a host's IP software treats an ongoing packet as incoming.
100
What is a Non-Routable IP Address?
A private IP Address sued for a device on a private network hidden behind a router or firewall.
101
What is a Routable IP Address?
A public IP address that is registered under the DNS.
102
What does DHCP stnad for?
Dynamic Host Configuration Protocol
103
What is the DHCP Protocol?
A protocol for allocating unique dynamic IP addresses for computers on a local netork when the local network attempts to connect to the internet.
104
What does NAT stand for?
Network Address Translation
105
What is the Network Address Translation?
The process o mapping a private IP address to a public IP address by modifying the address information in the packet header when the packet is sent through the router.
106
What is Port Forwarding?
The process of routing data through additional ports to allow a server in a non-routable network to provide services to the Internet.
107
What is the Client Server Model?
A model where the client sends a request message to the server, and the server responds to the request by replying with a response message to the client.
108
What is CRUD?
A web application with create, retrieve, update and delete functionality.
109
What are the 4 operations of CRUD?
- Create
- Retreive
- Update
- Delete
110
What does XML stand for?
Extension Markup Language
111
What is XML?
A markup language for encoding documents to be sent over a network in a human-readable and machine-readable format.
112
What does JSON stand for?
JavaSript Object Notation
113
What is JSON?
A human-readable file format used for transmitting information in attribute-value pairs and arrays.
114
What are the Advantages of XML?
- Any data type allowed so more flexible.
115
What are the Disadvantages of XML?
- Expansive use of tags make it more difficult to follow.
116
What are the Advantages of JSON?
- Easier for a human to read, write and maintain.
- More compact so reuqires less storage and quicker to transmit and process.
- Can be directly manipulated by JavaScript.
117
What are the disadvantages of JSON?
Works with a limited range of data types.
118
What does REST stand for?
REpresentational State Transfer
119
What is REST?
A Representational State Transfer methodology used to map a network's functionality to database operations.
120
What is the Web Socket Protocol?
A protocol specification which defines an API, establishing a full-duplex 'socket' connection between a web browser and a server over TCP. This creates a persistent connection between client and server.
121
What is Thick Client Computing?
A network where the clients have sufficient processing power and storage to handle its requests, while the server acts as external storage.
122
What is Thin Client Computing?
A network where a powerful, central server computer contains the majority of the processing power and storage capacity to handle client requests.
123
What is a Proxy Server?
A Proxy Server sits between the client devices and the firewall, providing anonymity to the clients, keeping their true IP Addresses hidden. It also speeds up performance by caching websites.
124
What is Stateless Inspection also known as?
Static Filtering
125
What is Stateless Inspection?
Uses a simple list of IP Addresses, ports and protocols to block unwanted traffic.
126
What is Stateful Inspection also known as?
Dynamic Filtering
127
What is Stateful Inspection?
It keeps track of open conversations in a connection table, and checks the packet payloads for suspicious activity. Is more effective against cyberattacks.
128
What does API stand for?
Application Programming Interface
129
What is an API?
An API is a set of protocols which define how two applications can interact with each other.
It outlines the format that messages can occur both in terms of the requests it is happy to receive and the responds it can send.
130
What is the WebSocket Protocol?
An example of a modern API used for comunication, typically, but not limited to use with a webserver.
