Everything! Flashcards
(147 cards)
1
Q
Once added to a blockchain, records….
A
cannot be changed
2
Q
Packet trailer contains
A
Error checking
3
Q
Convert 0111 to denary
A
7
4
Q
Name 4 facts about the binary number system
A
- 0 or 1 (2 digits)- Base 2- Used by computers- Uses more digits for the same number
5
Q
URL
A
uniform resource locator
6
Q
What are robots?
A
A robot is a mechanical device that performs an action
7
Q
What are some examples of real-world robots?
A
Drones and manufacturing robots
8
Q
Cryptocurrency payments over the internet are secure because
A
they are encrypted
9
Q
Blockchains are accessible by…
A
every connected computer
10
Q
Advantages of packets/packet switching
A
Easier to control than a stream of data, packets can go different routes in case route is busy/broken and allows high transmission of data
11
Q
Bank of England and Bank of Korea are examples of
A
central banks
12
Q
Convert 1011 to denary
A
11
13
Q
What’s a text address used to access websites?
A
URL
14
Q
Name 4 facts about the denary number system
A
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, (10 digits)- Base 10- Used by humans- Uses less digits for the same number
15
Q
All websites and webpages are known as
A
the world wide web (www)
16
Q
Payments can be sent digitally over the internet using…
A
Credit cards, Paypal, Apple Pay, Kakaopay and more!
17
Q
How are robots controlled?
A
They can be controlled by a person, automated or a mixture
18
Q
Payments are made for cryptocurrencies using…
A
blockchain
19
Q
The central authority for currencies are
A
banks
20
Q
The world wide web the name for
A
all websites and webpages
21
Q
Packet headers contain
A
sender IP address, receiver IP address, size in bytes
22
Q
Computers store everything as __________
A
binary
23
Q
Blockchains record…
A
All payments with time and date stamps
24
Q
A collection of webpages is called
A
a website
25
What is a USB port?
A socket in a device/computer that allows you to plug in a cable
26
What number system do these facts describe?- 0 or 1 (2 digits)- Base 2- Used by computers- Uses more digits for the same number
Binary
27
CPUs are made of billions of _______
switches
28
A blockchain is like a
digital ledger or list of all records of payment
29
Name 5 types of data
sound, video, images, text, numbers, facts
30
Banks are the ________ _________ for currencies
central authority
31
URLs are made up of 3 things....
protocol, domain, webpage
32
Packets are made up of
Header / Payload (Data) / Trailer
33
_______ -> process -> information
data -> process -> information
34
What are sound, video, images, text, numbers, facts known as?
types of data
35
Convert 1101 to denary
13
36
What are advantages of USBs?
simple interface - cable only works one way so less chance of errors // relatively high speed data transfer // universal - lots of devices use USB // can be used for power // automatically detected by computer to transfer
37
What are disadvantages of USBs?
Cables are limited to 5m usually // not as fast as other cables e.g. network cables
38
Packet payload contains
The actual data (around 64kb)
39
Packets are used to....
Send data from one device to another over a network
40
What are some other areas where you might find robots?
Medicine, agriculture, transport, industry, entertainment and domestic
41
An infrastructure is a way of describing
the internet
42
No central authority is also called
Decentralised
43
Inside every computer is a ______
CPU
44
data -> process -> _________
data -> process -> information
45
What are the features of a robot?
Sensors, mechanical structure, actuators and microprocessor
46
Examples of cryptocurrencies are
bitcoin, dogecoin, ethereum, cardano
47
Convert 1001 to denary
9
48
How does packet switching work?
Each packet broken down at sender, sent independently, route decided by routers, receiver reassembles
49
What kinds of USB are there?
USB ports, USB cables, USB connections, USB devices
50
bitcoin, dogecoin, ethereum, cardano are examples of
cryptocurrencies
51
What has no central authority for payments?
cryptocurrencies
52
Blockchain is how _________ payments are made
Cryptocurrency
53
What are some advantages of robots?
strength, repetition, work in dangerous or extreme places, consistent, can work 24/7
54
analogue data is experienced by _________
humans
55
What's a USB connection?
Anything that uses a USB cable plugged into a port
56
In robots what is the microprocessor for?
To take the reading from the sensor and then decide what to do
57
What can you do on the internet?
send/receive emails, chatting (video, text, audio), share files
58
USB
Universal Serial Bus
59
Packets are sent along different ________
routes
60
Protocol, domain and webpage are part of....
URLs
61
In robots, what are actuators?
Actuators make it move - its arms, wheels or attachments
62
The internet uses transmission _________ and internet ___________
protocols
63
The internet can be described as....
an infrastructure
64
Every website and webpage has a
URL
65
What's a USB device?
Anything that plugs into a USB port
66
data -> ________ -> information
data -> process -> information
67
In robots, what is the mechanical structure?
the body
68
Websites are a collection of
webpages
69
What are some disadvantages of robots?
Expensive to buy, expensive to maintain, require a lot of power, take human jobs, limited by their programming
70
What's a USB cable?
Type of cable that transmits data OR provides power
71
Digital payments over the internet are secure because they are
Encrypted
72
Decentralised
means no central authority
73
In robots, what do sensors do?
Record its environment
74
Data is sent from one device to another over a network using ___________
packets
75
An example of a central bank is....
Bank of England, Bank of Korea
76
Cryptocurrency has no ________ _________
central authority
77
Computers convert ________ data to ________ data
Computers convert analogue data to digital data
78
humans experience _________ data in the real world
analogue
79
All parts connected in a huge network is called an
infrastructure
80
An infrastructure means all...
parts are connected in a huge network
81
What number system do these facts describe?- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, (10 digits)- Base 10- Used by humans- Uses less digits for the same number
Denary
82
What does text have to be converted to to be processed by a computer?
binary
83
What do computers process all data as?
binary
84
What does a computer use to convert text to binary?
a character set
85
What do computers use character sets for?
To convert text to binary
86
What are the two main types of character sets?
ASCII and UNICODE
87
What are ASCII and UNICODE
Two main types of character sets to convert text to binary
88
What is ASCII used for?
Represents characters using 8-bit binary numbers
89
What's a disadvantage of ASCII?
Its limited to 256 characters
90
UNICODE can represent characters using .....
8, 16 or 32-bit binary numbers
91
Why do we use UNICODE?
To allow more characters, alphabets and symbols like emojis
92
How do we allow more characters, alphabets and symbols like emojis?
UNICODE
93
Sound is a____________
analogue
94
Sound waves need to be __________ to be stored in a computer
sampled
95
Sampling happens at
regular time intervals
96
Sampling rate =
number of samples per second (in hertz, Hz)
97
Higher sampling rate or larger resolution =
better quality sound, larger file size
98
Name 3 drawbacks of larger sampling resolution when recording sound
larger file size, takes longer to transmit/download data, requires greater processing power
99
Name 3 benefits of larger sampling resolution when recording sound
larger dynamic range, better sound quality, less sound distortion
100
bits per sample =
sampling resolution / bit depth
101
Pixels are represented in
binary
102
Black and white images only require ______ per pixel
1 bit
103
Number of bits used to represent each colour is called
colour depth
104
Image resolution means
pixels high vs pixels wide
105
Lower image resolution means
Less image detail
106
Whats the main drawback of using high resolution images?
Increase in file size
107
Colours are created using different amounts of
Red Green and Blue (RGB)
108
What does encryption mean?
Encryption alters the data into a form that is unreadable by strangers
109
Scrambles data for secure transmission
encryption
110
What does encryption mean?
Encryption alters the data into a form that is unreadable by strangers
111
Scrambles data for secure transmission
encryption
112
Why is encryption effective?
If the data is stolen it's meaningless
113
What is the purpose of encryption?
There's always a risk of interception when transmitting data over a public network, encryption reduces the risk
114
What's plaintext?
the original data being sent
115
What's ciphertext?
Plaintext after it goes through encryption algorithm
116
Plaintext is
Not secure
117
Ciphertext is
Much more secure
118
Plaintext can be read by ________
anyone
119
Ciphertext means
Text is scrambled using a secret formula
120
Turning plain text to cipher text is called
Encryption
121
Turning cipher text back to plain text is called
Decryption
122
What are the two main types of encryption?
Symmetric and asymmetric
123
What is symmetric encryption?
Same key used for encrypting and decrypting
124
Why use symmetric encryption?
For encrypting on your own computer
125
Why isn't symmetric encryption used over networks?
Easy for a hacker to intercept cipher and key
126
What is asymmetric encryption?
Public and private keys are used, more secure over networks
127
How does asymmetric encryption work?
Plain text encrypted via public key, transmitted, decrypted using private key
128
What are real world examples of encryption?
HTTPS in browsers, bank transactions
129
How do you make an encryption key more secure?
Increase the number of bits used in the key (e.g. 64 - > 128 bit)
130
Same key used for encrypting and decrypting
Symmetric encryption
131
Public and private keys are used, more secure over networks
Asymmetric encryption
132
What are cookies?
Small files or code stored on a user's computer
133
What are small files or code sent from a webserver and stored on a users computer
Cookies
134
Everytime a user visits a website, the site checks if it has set _______ on their ________ before
Everytime a user visits a website, the site checks if it has set cookies on their browser before
135
What are the two types of cookies?
Session and persistent
136
What are session and persistent types of ?
Cookie
137
Which cookie is temporary and don't collect or store user information?
Session cookies
138
Name two facts about session cookies
Temporary, don't store/collect user info
139
Which cookies cease to exist when a browser is closed?
Session cookies
140
Session cookies _____ to ______ when a browser is closed
cease to exist
141
What are session cookies used for?
Temporary shopping baskets
142
Which cookies are used for temporary shopping baskets?
Session cookies
143
____ cookies are stored on the hard drive of a users computer
persistent cookies
144
Which cookies have an expiry date or stay until deleted?
persistent cookies
145
Which cookies remain even after the browser is closed?
persistent cookies
146
What are persistant cookies used for?
Allow website to remember usernames, passwords, emails, baskets, preferences
147
What kind of user preferences do cookies hold?
language, currency, login
