Everything! Flashcards
Once added to a blockchain, records….
cannot be changed
Packet trailer contains
Error checking
Convert 0111 to denary
7
Name 4 facts about the binary number system
- 0 or 1 (2 digits)- Base 2- Used by computers- Uses more digits for the same number
URL
uniform resource locator
What are robots?
A robot is a mechanical device that performs an action
What are some examples of real-world robots?
Drones and manufacturing robots
Cryptocurrency payments over the internet are secure because
they are encrypted
Blockchains are accessible by…
every connected computer
Advantages of packets/packet switching
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
Bank of England and Bank of Korea are examples of
central banks
Convert 1011 to denary
11
What’s a text address used to access websites?
URL
Name 4 facts about the denary number system
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, (10 digits)- Base 10- Used by humans- Uses less digits for the same number
All websites and webpages are known as
the world wide web (www)
Payments can be sent digitally over the internet using…
Credit cards, Paypal, Apple Pay, Kakaopay and more!
How are robots controlled?
They can be controlled by a person, automated or a mixture
Payments are made for cryptocurrencies using…
blockchain
The central authority for currencies are
banks
The world wide web the name for
all websites and webpages
Packet headers contain
sender IP address, receiver IP address, size in bytes
Computers store everything as __________
binary
Blockchains record…
All payments with time and date stamps
A collection of webpages is called
a website
What is a USB port?
A socket in a device/computer that allows you to plug in a cable
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
CPUs are made of billions of _______
switches
A blockchain is like a
digital ledger or list of all records of payment
Name 5 types of data
sound, video, images, text, numbers, facts
Banks are the ________ _________ for currencies
central authority
URLs are made up of 3 things….
protocol, domain, webpage
Packets are made up of
Header / Payload (Data) / Trailer
_______ -> process -> information
data -> process -> information
What are sound, video, images, text, numbers, facts known as?
types of data
Convert 1101 to denary
13
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
What are disadvantages of USBs?
Cables are limited to 5m usually // not as fast as other cables e.g. network cables
Packet payload contains
The actual data (around 64kb)
Packets are used to….
Send data from one device to another over a network
What are some other areas where you might find robots?
Medicine, agriculture, transport, industry, entertainment and domestic
An infrastructure is a way of describing
the internet
No central authority is also called
Decentralised
Inside every computer is a ______
CPU
data -> process -> _________
data -> process -> information
What are the features of a robot?
Sensors, mechanical structure, actuators and microprocessor
Examples of cryptocurrencies are
bitcoin, dogecoin, ethereum, cardano
Convert 1001 to denary
9
How does packet switching work?
Each packet broken down at sender, sent independently, route decided by routers, receiver reassembles
What kinds of USB are there?
USB ports, USB cables, USB connections, USB devices
bitcoin, dogecoin, ethereum, cardano are examples of
cryptocurrencies
What has no central authority for payments?
cryptocurrencies
Blockchain is how _________ payments are made
Cryptocurrency
What are some advantages of robots?
strength, repetition, work in dangerous or extreme places, consistent, can work 24/7
analogue data is experienced by _________
humans
What’s a USB connection?
Anything that uses a USB cable plugged into a port
In robots what is the microprocessor for?
To take the reading from the sensor and then decide what to do
What can you do on the internet?
send/receive emails, chatting (video, text, audio), share files
USB
Universal Serial Bus
Packets are sent along different ________
routes
Protocol, domain and webpage are part of….
URLs
In robots, what are actuators?
Actuators make it move - its arms, wheels or attachments
The internet uses transmission _________ and internet ___________
protocols
The internet can be described as….
an infrastructure
Every website and webpage has a
URL
What’s a USB device?
Anything that plugs into a USB port
data -> ________ -> information
data -> process -> information
In robots, what is the mechanical structure?
the body
Websites are a collection of
webpages
What are some disadvantages of robots?
Expensive to buy, expensive to maintain, require a lot of power, take human jobs, limited by their programming
What’s a USB cable?
Type of cable that transmits data OR provides power
Digital payments over the internet are secure because they are
Encrypted
Decentralised
means no central authority
In robots, what do sensors do?
Record its environment
Data is sent from one device to another over a network using ___________
packets
An example of a central bank is….
Bank of England, Bank of Korea
Cryptocurrency has no ________ _________
central authority
Computers convert ________ data to ________ data
Computers convert analogue data to digital data
humans experience _________ data in the real world
analogue
All parts connected in a huge network is called an
infrastructure
An infrastructure means all…
parts are connected in a huge network
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
What does text have to be converted to to be processed by a computer?
binary
What do computers process all data as?
binary
What does a computer use to convert text to binary?
a character set
What do computers use character sets for?
To convert text to binary
What are the two main types of character sets?
ASCII and UNICODE
What are ASCII and UNICODE
Two main types of character sets to convert text to binary
What is ASCII used for?
Represents characters using 8-bit binary numbers
What’s a disadvantage of ASCII?
Its limited to 256 characters
UNICODE can represent characters using …..
8, 16 or 32-bit binary numbers
Why do we use UNICODE?
To allow more characters, alphabets and symbols like emojis
How do we allow more characters, alphabets and symbols like emojis?
UNICODE
Sound is a____________
analogue
Sound waves need to be __________ to be stored in a computer
sampled
Sampling happens at
regular time intervals
Sampling rate =
number of samples per second (in hertz, Hz)
Higher sampling rate or larger resolution =
better quality sound, larger file size
Name 3 drawbacks of larger sampling resolution when recording sound
larger file size, takes longer to transmit/download data, requires greater processing power
Name 3 benefits of larger sampling resolution when recording sound
larger dynamic range, better sound quality, less sound distortion
bits per sample =
sampling resolution / bit depth
Pixels are represented in
binary
Black and white images only require ______ per pixel
1 bit
Number of bits used to represent each colour is called
colour depth
Image resolution means
pixels high vs pixels wide
Lower image resolution means
Less image detail
Whats the main drawback of using high resolution images?
Increase in file size
Colours are created using different amounts of
Red Green and Blue (RGB)
What does encryption mean?
Encryption alters the data into a form that is unreadable by strangers
Scrambles data for secure transmission
encryption
What does encryption mean?
Encryption alters the data into a form that is unreadable by strangers
Scrambles data for secure transmission
encryption
Why is encryption effective?
If the data is stolen it’s meaningless
What is the purpose of encryption?
There’s always a risk of interception when transmitting data over a public network, encryption reduces the risk
What’s plaintext?
the original data being sent
What’s ciphertext?
Plaintext after it goes through encryption algorithm
Plaintext is
Not secure
Ciphertext is
Much more secure
Plaintext can be read by ________
anyone
Ciphertext means
Text is scrambled using a secret formula
Turning plain text to cipher text is called
Encryption
Turning cipher text back to plain text is called
Decryption
What are the two main types of encryption?
Symmetric and asymmetric
What is symmetric encryption?
Same key used for encrypting and decrypting
Why use symmetric encryption?
For encrypting on your own computer
Why isn’t symmetric encryption used over networks?
Easy for a hacker to intercept cipher and key
What is asymmetric encryption?
Public and private keys are used, more secure over networks
How does asymmetric encryption work?
Plain text encrypted via public key, transmitted, decrypted using private key
What are real world examples of encryption?
HTTPS in browsers, bank transactions
How do you make an encryption key more secure?
Increase the number of bits used in the key (e.g. 64 - > 128 bit)
Same key used for encrypting and decrypting
Symmetric encryption
Public and private keys are used, more secure over networks
Asymmetric encryption
What are cookies?
Small files or code stored on a user’s computer
What are small files or code sent from a webserver and stored on a users computer
Cookies
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
What are the two types of cookies?
Session and persistent
What are session and persistent types of ?
Cookie
Which cookie is temporary and don’t collect or store user information?
Session cookies
Name two facts about session cookies
Temporary, don’t store/collect user info
Which cookies cease to exist when a browser is closed?
Session cookies
Session cookies _____ to ______ when a browser is closed
cease to exist
What are session cookies used for?
Temporary shopping baskets
Which cookies are used for temporary shopping baskets?
Session cookies
____ cookies are stored on the hard drive of a users computer
persistent cookies
Which cookies have an expiry date or stay until deleted?
persistent cookies
Which cookies remain even after the browser is closed?
persistent cookies
What are persistant cookies used for?
Allow website to remember usernames, passwords, emails, baskets, preferences
What kind of user preferences do cookies hold?
language, currency, login