The Internet and the World Wide Web (WWW)

1. Difference Between the Internet and the WWW

• The Internet is a vast network of connected computers and other devices worldwide. It allows different networks to communicate with each other.

• The World Wide Web (WWW) is just a part of the Internet. It consists of web pages that can be accessed using web browsers.

• The WWW works through a system called Hypertext Transfer Protocol (HTTP), which allows users to browse and retrieve information.

In short:

• Internet = a huge network that connects devices.

• WWW = a collection of websites that use the Internet to function.

2. URLs (Uniform Resource Locators)

• A URL is a website's address that helps users find specific web pages.

• It follows this format:

protocol://website address/path/file name

• Example: https://www.hoddereducation.co.uk/ict

• The protocol tells how data should be sent (e.g., http or https).

• The website address consists of:

  • Domain host (e.g., www)

  • Domain name (e.g., hoddereducation)

  • Domain type (.com, .org, .gov, etc.)

  • Country code (e.g., .uk, .de, .us)

3. HTTP and HTTPS

• HTTP (Hypertext Transfer Protocol) is a set of rules that allow files to be shared over the Internet.

• HTTPS (Secure HTTP) is the safer version, using encryption to protect information (such as passwords or payment details).

4. Web Browsers

• Web browsers are programs that help users access and view websites.

• Browsers read HTML (Hypertext Markup Language) to display images, text, videos, and audio.

Common Features of Web Browsers:

• A home page that appears when the browser opens.

• Bookmarks to save favorite websites.

• History to keep track of visited sites.

• Navigation buttons (back, forward, refresh).

• Tabs to open multiple web pages at once.

• Cookies to store website data (explained below).

• Hyperlinks (clickable links) to jump between web pages.

5. How Web Pages Are Retrieved (DNS Process)

• Websites are stored on web servers with unique addresses called IP addresses (e.g., 107.162.140.19).

• Instead of remembering IP addresses, we use domain names (like www.google.com).

• The Domain Name System (DNS) translates domain names into IP addresses.

Steps of the DNS Process:

1. User types a website URL into the browser.

2. The browser asks a DNS server for the website's IP address.

3. If the first DNS server doesn’t have it, it asks another DNS server.

4. Once the IP address is found, it is sent back to the user’s computer.

5. The computer then connects to the website’s server, downloads the web page, and displays it in the browser.

6. Cookies

Cookies are small files stored on a user’s computer by websites. They remember information about the user’s activity.

Types of Cookies:

• Session Cookies:

  • Store temporary information (like shopping cart items).

  • Disappear when the browser is closed.

• Persistent Cookies:

  • Store long-term information (like login details and preferences).

  • Stay on the device until deleted or expired.

Uses of Cookies:

• Remember login details (so users don’t have to enter them every time).

• Keep items in a shopping cart.

• Track browsing habits for personalized recommendations.

• Store language and display preferences.

• Help with online financial transactions.

• Save progress in online games and quizzes.

Digital Currency

5.2.1 What Is Digital Currency?

• Digital currency exists only in electronic form, unlike physical cash.

• It is used to make payments online, transfer money between accounts, and conduct financial transactions.

• Examples: PayPal, Apple Pay, Google Pay, AliPay, weChat Pay

• Digital currency is usually centralized, meaning banks and governments regulate transactions.

5.2.2 Cryptocurrency and Blockchain

• Cryptocurrency is a type of digital currency that is decentralized, meaning no single entity (like a bank) controls it.

• Uses cryptography for secure transactions.

• Examples: Bitcoin, Ethereum.

What Is Blockchain?

• A decentralized digital ledger that records transactions across many computers.

• Each transaction is stored in a block, and blocks are linked to form a chain.

• Every computer in the network has a copy of the blockchain, making it secure and hard to hack.

How Blockchain Works

1. A new transaction is created.

2. A new block is generated with a unique hash (security code).

3. The block is verified by multiple computers in the network.

4. Once verified, it is added to the blockchain permanently.

5. The process is controlled by miners, who validate transactions and are rewarded with cryptocurrency.

Uses of Blockchain

✔ Cryptocurrency (Bitcoin, Ethereum)
✔ Smart Contracts (automated agreements)
✔ Medical Research (secure data storage)
✔ Voting Systems (tamper-proof elections)
✔ Education (secure academic records)

Cybersecurity and Threats

Keeping data safe is crucial, whether it’s personal or business-related. Cyber threats can lead to data loss, theft, or corruption through accidental damage or malicious attacks. Here are some common cybersecurity threats:

1. Brute Force Attacks

Hackers try different password combinations until they crack one. They often start with common passwords like 123456 or password. Strong, long passwords with a mix of characters make it harder for attackers.

2. Data Interception

Hackers steal data by intercepting network traffic using:

• Packet sniffers (monitor wired network traffic)

• Wardriving (intercepting Wi-Fi signals using a laptop and special software)

🔒 Prevention: Encrypt data, use strong Wi-Fi passwords, and avoid public Wi-Fi.

3. Distributed Denial of Service (DDoS) Attacks

Hackers flood a network or website with fake requests, making it unavailable for real users.

🔒 Prevention: Firewalls, spam filters, and malware protection help reduce risk.

4. Hacking

Unauthorized access to computer systems can lead to data theft, corruption, or loss.

🔒 Prevention: Firewalls, strong passwords, encryption, and intrusion detection software.

5. Malware (Malicious Software)

Different types of malware include:

• Viruses – Attach to files, corrupt or delete data.

• Worms – Spread across networks without user action.

• Trojan Horses – Disguised as legitimate software but cause harm.

• Spyware – Tracks user activity and steals sensitive data.

• Adware – Bombards users with unwanted ads.

• Ransomware – Encrypts files and demands payment for access.

🔒 Prevention: Use antivirus software, avoid suspicious emails/websites, and regularly back up data.

6. Phishing

Fake emails trick users into revealing sensitive information or clicking malicious links.

🔒 Prevention:

• Don't click on unknown links.

• Look for https and a padlock icon in the address bar.

• Use anti-phishing tools.

7. Pharming

Malicious code redirects users to fake websites to steal data. Unlike phishing, users don’t need to take any action for this to happen.

🔒 Prevention:

• Use antivirus software.

• Double-check website URLs.

• Ensure sites use https or show a padlock icon.

Cybersecurity: Social Engineering, Access Levels, and Protection Measures

Social Engineering

Social engineering tricks people into bypassing security measures by exploiting emotions like:

• Fear – Urgency scares victims into making quick, unsafe decisions.

• Curiosity – Fake prizes or abandoned USB drives tempt users into revealing information.

• Trust – Victims assume emails or calls from familiar companies are legitimate.

Stages of a Social Engineering Attack

1. Targeting – Cybercriminals gather information and choose a method.

2. Attack – The victim is approached via email, phone, or malware.

3. Execution – The hacker gains access or steals information.

4. Cover-up – Malware is removed to erase evidence.

Keeping Data Safe

Access Levels

Systems assign different levels of access to protect data:

• Public Access – Open to anyone.

• Friends – Limited to approved users.

• Custom – Specific data is restricted from certain people.

• Owner – Only the data creator can see everything.

For example, in a hospital, only authorized staff can view patient records. Social media platforms also use access levels for privacy control.

Anti-Malware Protection

Two key types of anti-malware:

• Antivirus – Detects and removes harmful software.

• Antispyware – Prevents programs from tracking user activity.

🔒 Key Features of Antispyware:
✔ Detects and removes spyware
✔ Prevents spyware downloads
✔ Encrypts data and keystrokes to block keyloggers
✔ Protects webcams and microphones from unauthorized access
✔ Scans for stolen personal data

Authentication: Proving Identity

To access secure data, authentication relies on:

1. Something You Know – Passwords or PIN codes.

2. Something You Have – A phone or security token.

3. Something Unique to You – Biometrics like fingerprints.

Strong Passwords Matter!

A good password should:
✔ Contain uppercase letters, numbers, and symbols (@, *, &)
✔ Be changed regularly
✔ Avoid personal details like pet names or birthdays

Example:
✅ Strong: Sy12@#TT90kj=0
❌ Weak: GREEN

Systems often:

• Hide passwords as ***** on screens.

• Limit login attempts before locking accounts.

• Require password confirmation when resetting credentials.

By following these security measures, users can better protect themselves from cyber threats.

Biometrics: Secure User Identification

Biometrics is a security method that verifies identity based on unique human characteristics, such as:

• Fingerprint scans

• Retina scans

• Face recognition

• Voice recognition

Applications of Biometrics

Biometric security is used in various fields:

• Mobile phones – Fingerprint scanning for unlocking devices.

• Secure facilities – Pharmaceutical companies use retina or face scans for restricted access.

Detailed Biometric Methods

Fingerprint Scanning

Compares fingerprint patterns against stored data. Accuracy: 1 in 5,000.

✅ Benefits:
✔ Unique to each person, enhancing security.
✔ Cannot be lost or stolen like ID cards.
✔ Prevents unauthorized sign-ins.

❌ Drawbacks:
✖ Expensive to install.
✖ Injuries or dirt can affect accuracy.
✖ Some view it as an invasion of privacy.

Retina Scanning

Uses infrared light to map blood vessels in the eye. Accuracy: 1 in 10 million.

✅ Benefits:
✔ Extremely secure—retina patterns cannot be duplicated.

❌ Drawbacks:
✖ Intrusive and uncomfortable.
✖ Slow scanning process.
✖ High cost of installation.

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