5. internet and its uses Flashcards
what is the internet
a huge, public network of computer systems, and is the physical infrastructure that allows data to travel across the globe
what physical attributes make up the internet
Computers
Servers
Switches
Routers
Cables
what is the world wide web
The resources located on the internet, such as web pages
The world wide web is accessed using the internet; you need an internet connection in order to access the world wide web.
what are the different types of resources on the www
Web pages
Documents
Images
Videos
Music
Emails
what is a URL
uniform resource locator
A text-based address for a web page containing the protocol, domain and web page/file name.
Some URLs also contain a file path between the domain name and the file name, separated by forward slash characters.
what are the parts of the url in the following example:
https://www.site24x7.com/science/find-ip-address-of-web-site.html
protocal- https
domain name- site24x7.com
file path- science
web page/ file name- find-ip-address-of-web-site.html
what are the types of web protocals
http and https
http
hypertext transfer protocal
a protocol used to transfer resources, such as web pages, via the world wide web.uses request codes to send and receive data and perform other various tasks such as: GET, PUT, DELETE, POST
https
hypertext transfer protocal secure
a secure method of sending data via the world wide web, and was invented to combat the glaring security risk of sending sensitive data via the HTTP protocol
operates by using encryption to obfuscate data, using a method called Transport Layer Security (TLS). TLS uses a method called asymmetric public key infrastructure, with a public and private key
Explain the purpose and functions of a web browser
The main purpose of a web browser is to render
hypertext markup language (HTML) and display
web pages
- Functions include:
– storing bookmarks and favourites
– recording user history
– allowing use of multiple tabs
– storing cookies
– providing navigation tools
– providing an address bar
Describe how web pages are located, retrieved and displayed on a device when a user enters a URL
1-user enters the URL into the web browser’s address bar.
2-URL points to a web page or resource on the world wide web. However, computers connected to the internet communicate with each other using their IP addresses. All computer systems connected to the internet will have their own, unique IP address
3-DNS domain name system, keeps record of all domain names, maps each domain name to a IP address. If DNS doesnt have this domain name it goes to the other until domain found
4- once iP address found to the requested domain name, web browser visits IP address in question and requests web page or resource usually residing in web server
5- web server will either allow or disallow access to the resource, depending on the nature of the request.
6-if request granted, web server returns the resource to the web browser usually RAW html, web browser translates into readable format to user
what are cookies
are small pieces of data that are stored on the users’ computer system, and are used by the web browser
why are cookies stored?
Saving personal details
Tracking user preferences
Holding items in a shopping cart
Storing login details
what are persistent cookies
A cookie that is stored long-term on the computer system.
often used to store login details for websites, meaning the user does not have to enter their credentials upon each visit
what are session cookies
A cookie that is deleted after closing the browser, exists in memory, stored in RAM.
typically used while browsing sensitive information on the world wide web, such as online banking, e-commerce or similar.
what are digital currencies?
a currency that only exists electronically, and have no physical attributes but has a cryptographically assigned value, using complex algorithms and mathematics.
what are some characteristics of digital currencies
-decentralised (Transactions are processed by an open network that no single person owns.)
-irreversible and public (clear understanding of where the funds have travelled to and from, as well as the amount, person who owns the currency only one allowed to move said currency)
-anonymous (sending and receiving currency is anonymous, and simply requires a digital wallet and a wallet address)
-limit supply(a limited supply and circulation of digital currency)
how are digital currencies used?
1- user must sign up to a digital currency exchange. This is essentially a place where users can purchase digital currency using traditional currency
2-Once a currency has been purchased, it resides in the user’s digital wallet. The user can send this currency to another digital wallet using a unique wallet address
3-The user will send the Bitcoin to the wallet address – which is recorded on the blockchain – and is received in the recipient’s wallet.
what is a blockchain?
is a digital ledger, that is a time-stamped series of records that cannot be altered.
Each connecting block is chronologically linked to one another, providing a reliable record of events
If anyone attempts to change the contents of a data block, a brand new one is added.
it is completely tamper-proof and always independently verified
what information does each block in a blockchain contain?
Sender wallet address
Receiver wallet address
Amount sent
Network fee (the cost of sending the digital currency using the blockchain)
Timestamp
Number of confirmations – mutual ‘agreements’ between multiple blockchain nodes adding details of the same transaction
most common cyber security threats
-brute-force attack
– data interception
– distributed denial of service (DDoS) attack
– hacking
– malware (virus, worm, Trojan horse, spyware,
adware, ransomware)
– pharming
– phishing
– social engineering
social engineering
art of manipulating or ‘conning’ individuals into giving away private information or login IDs and passwords eg phishing
phishing
act of sending a malicious email to a target user, with the intent of stealing information from them
brute force attacks
a hacker may go through a list of the most common passwords until access to an account is gained. This is usually automated using common hacking tools. Alternatively, the attacker may try every combination of characters until the correct password is found