unit 5 Flashcards
what is the internet
huge public network of computer systems
allows for the flow of information between devices
made up of computers, servers, switches and routers
what is the world wide web
the collection of resources that exist on the internet
what is a URL(Uniform resource locator)
they are text based addresses for web pages
used instead of IP addresses
what are URL’s made of
protocol(HTTP OR HTTPS)
domain name
web page
what is HTTP(Hypertext transfer protocol)
used to transfer resources
uses request codes to send and recieve data and perform other tasks
what are the different request codes
GET, POST, DELETE, PUT
what is the GET request code
request the web server to transmit a specific resource
what is the POST request code
requests to add content or data to a new page
what is the DELETE request code
removes the specified resource form the web server
what is the PUT request code
modifies an existing resource
what is a disadvantage of HTTP
any data sent by this protocol can be read by anyone
what is HTTPS(Hypertext transfer protocol secure)
secure method of sending data
done through asymmetric encryption
what are web browsers
allows us to surf the web and view web pages
they render HTML web pages and display the content
what are functions of web browsers
storing bookmarks and favorites
recording user history
allowing use of multiple tabs
storing cookies
providing navigation tools
providing an address bar
what is a DNS server
domain name system
keeps record of all domains in existence and maps each of these domains to an IP address
what happens if the DNS server does not have the requested IP address
it will request it from another DNS server
what is a web server
a computer system connected to the internet which stores multiple resources
what do web servers store
web pages
images
videos
audio files
interactive content
what happens when the web browser wants a resource
the web browser finds the correct IP address and then request the resource from the web server
it will then send the HTML which the browser turns into a readable form for the user
what are cookies and what do they do
small pieces of data that are stored on the users computer system
saves personal details
tracks user preferences
holds items in online shopping
stores login details
what are persistent cookies
they remove the need to alter settings on every visit to a website
they are stored on the HDD
what are session cookies
stored temporarily on the computer system
stored in RAM
used to track the user in particular websites
what is digital currency
a form of currency that only exists digitally
what are characteristics of digital currency
decentralised- not controlled by any banks or authorities
irreversible and public- they are on a public record and only the person who owns their currency can move it
anonymous-sending and recieving digital currency is anonymous
limited supply- there is limited supply and circulation of digital currency
advantages of digital currency
anonymous
decentralised
anyone can access it
no middle man taking the cut
cannot be manipulated
disadvantages of digital currency
uses lots of resources to compute the hashes required
some digital currencies are not accepted widely
not a traditional bank
investors have turned digital currency into a commodity
value tends to fluctuate
what is blockchain
a worldwide, synchronised system of digital ledgers
completely tamper proof
what happens when data needs to be added to blockchain
when data is added a new block is added to the chain
each connecting block is linked to one another which provides a reliable record of events
what do the blocks contain in blockchain
sender wallet address
receiver wallet address
amount sent
network fee
timestamp
number of confirmations
what is social engineering
the art of manipulating individuals into giving away private information
what is phishing
when a malicious email is sent to a target user with the intent of stealing information away from them
what are brute force attacks
hackers go through a list of commonly used passwords
how to stop brute force attacks
having very strong passwords
what is malware
software that can cause harm to a computer system
what can be done to stop malware
anti virus software should be installed on all computers
automatic updates are commonly used to keep anti virus software up to date
firewalls should be set up
users trained to avoid malware
what is DDoS( Distributed Denial of Service) attack
when a number of computer systems send a large amount of internet traffic towards a single server or system
the server gets knocked offline and becomes inaccessible to users
what is hacking
general term for gaining access to a computer system without authorisation
what is pharming
form of fraud that takes place online through malicious websites
user is sent to a fake website
what is data interception
when a malicious attacker intercepts data in transmit
what are access levels
ensures that users can only access their personal documents and documents that are related to them
what are count controlled loops
repeats loops a set number of times
what are pre controlled loops
repeats loop while a condition is true
what are post condition loops
repeats loop until a condition is true
what are the benefits of using files for file storage
reusability(output can be imported back into programs)
large storage capacity
portability
how can files be opened in python
open(<filename>,<mode>)</mode></filename>
how can files be closed in python
file.close()
what are the different modes with which files can be opened
read(r)
write(w)
append(a)
read/write(r+)
how to open file in pseudo code
OPENFILE <filename> FOR <file></file></filename>
how to close files in pseudocode
CLOSEFILE<filename></filename>
command to write to files in python
file.write(“\nwriteanything”)
