Internet and its uses

• Internet


  Global network of computers and other electronic devices connected together through a system of routers and servers
• World Wide Web


  Collection of websites and web pages that are accessed using the internet
• The World Wide Web was created in 1989 by Tim Berners-Lee, who envisioned it as a way to share and access information on a global scale
• URL


  Text-based address that identifies the location of a resource on the internet
• Components of a URL


  • Protocol
  • Domain name
  • Web page / file name
• HTTP


  Protocol used for transferring data between a client and a server on the internet
• HTTPS


  Secure version of HTTP that uses encryption to protect data transferred between a client and a server
• SSL


  • Security protocol developed by Netscape in the 1990s to provide secure communication over the internet
• TLS


  • Successor to SSL, a security protocol used to provide secure communication over the internet
• TLS protocol


  1. Handshake Layer

  2. Record Layer
• Web browser


  Piece of software used to access and display information on the internet
• Functions of a web browser


  • Render HTML
  • Storing bookmarks and favourites
  • Recording user history
  • Allowing use of multiple tabs
  • Storing cookies
  • Providing navigation tools
  • Providing an address bar
  • Runs Active Scripts
  • Download Files
  • Request Web Pages
  • Manages Protocols
• How web pages are requested and displayed


  1. Browser sends URL to DNS

  2. DNS finds IP address and sends to browser

  3. Browser sends request to web server

  4. Browser interprets and renders HTML to display web pages
• HTML


  Language used to create the structure/layout of a website
• CSS


  Language used to create the presentation / formatting of the page
• Cookies are small files that are stored on a user's device by a website
• Functions of cookies


  • Saving Personal Details
  • Tracking User Preferences
  • Holding Items in an Online Shopping Basket
  • Storing Login Details
  • Storing Relevant Purchases
  • Displaying Relevant Adverts
  • Tracking Visitor Statistics
• Session cookies


  Temporary cookies stored only during a user's browsing session
• Persistent cookies


  Cookies stored on a user's device for a longer period, usually for a few weeks to several years
• Digital currency


  A type of currency that exists only in electronic form and is not backed by any physical commodity or government
• Digital currencies


  • Only exist electronically, not in physical form like cash or coins
  • Stored in digital wallets or accounts
  • Can be transferred electronically between individuals or businesses
• Digital currencies


  • Operate on a decentralised network, not controlled by any central authority like a government or financial institution
  • Transactions are verified and recorded on a public ledger known as a blockchain
• Uses of digital currencies


  • Purchasing goods and services online
  • Transferring money internationally
  • Investments
  • Store of value
• Volatility of digital currencies


  • Their value can fluctuate rapidly over short periods of time
  • This can make them risky investments and difficult to use as a stable store of value
• Examples of digital currencies


  • Bitcoin
  • Ethereum
  • Litecoin
  • Ripple
• Blockchain


  • A digital ledger that records every transaction made with a particular digital currency
  • Each transaction is time-stamped and added to the blockchain in a permanent and unalterable way
  • Decentralised technology, not controlled by a single entity or authority
  • Every participant in the network has a copy of the ledger and can verify the transactions independently
  • Made up of "blocks" of transactions that are linked together in a "chain" using cryptographic algorithms
  • Creates a secure and tamper-proof record of every transaction
  • Each transaction must be verified by multiple participants in the network to ensure legitimacy and prevent fraudulent activity
• Cyber Security Threats


  • Brute-Force Attack
  • Data Interception
  • Distributed Denial of Service (DDoS) Attack
  • Hacking
  • Malware
  • Phishing
  • Pharming
  • Social Engineering
  • Accidental Damage
• Brute-Force Attack


  A trial-and-error method used to crack passwords or encryption keys by trying every possible combination until the correct one is found
• Data Interception


  Eavesdropping on communication channels to intercept and steal sensitive information, such as passwords, credit card numbers, or personal data
• Distributed Denial of Service (DDoS) Attack


  Multiple computers are used as bots to flood a server with lots of requests at the same time which the server can't respond to; causing it to crash or become unavailable to users
• Hacking


  Gaining unauthorised access to a system or network to steal or manipulate data, disrupt services, or cause damage
• Types of Malware


  • Virus
  • Worm
  • Trojan horse
  • Spyware
  • Adware
  • Ransomware
• Phishing


  The user is sent an email which looks legitimate and contains a link to a fake website where the user is encouraged to enter their details
• Pharming


  Malware is downloaded without the user's knowledge that redirects the user to a fake website where they're encouraged to enter their personal details
• Social Engineering Techniques


  • Impersonation
  • Baiting
  • Pretexting
• Causes of Accidental Damage


  • Loss of power
  • Liquids being spilt
  • Flooding
  • Fire
  • Hardware failure
  • Software failure
  • Human error
• Access Levels


  Full access - user can open, create, edit & delete files

  Read-only access - user can only open files without editing or deleting

  No access - file is hidden from the user
• Anti-Malware


  • Scans files and compares them to a list of known malware, quarantines and deletes any malware found
• Authentication Methods


  • Passwords
  • Biometrics
  • Two-factor authentication (2FA)
• Automating Software Updates


  Scans the Internet for known updates to software and installs them automatically or notifies the user