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🔹 Introduction

The World Wide Web (WWW) is the largest information system in the world, consisting of web pages linked together through hyperlinks. Its communication is powered by two main protocols:

• HTTP – The foundational web communication protocol
• HTTPS – The secure, encrypted version of HTTP

Together, WWW + HTTP/HTTPS enable web browsing, online banking, e-commerce, video streaming, cloud access, and more.

1️⃣ WWW (World Wide Web)

The WWW is an enormous collection of distributed web resources such as web pages, images, videos, documents, and applications accessible through URLs.

✔ Components of WWW

• Web Clients – Browsers like Chrome, Firefox, Edge
• Web Servers – Apache, Nginx, IIS
• Web Pages – HTML, CSS, JavaScript
• Protocols – HTTP/HTTPS

✔ URL (Uniform Resource Locator)

A URL identifies the location of a resource on the Web.

✔ Working of WWW (Explained in Words)

Browser → Sends HTTP request → Web server → Sends content → Browser displays webpage

2️⃣ HTTP (HyperText Transfer Protocol)

HTTP is a stateless, text-based, client-server protocol used for transferring web documents.

✔ Features of HTTP

• Runs on port 80
• Stateless protocol (no memory between requests)
• Uses request–response model
• Supports caching, cookies, sessions

✔ HTTP Request Methods

• GET – Retrieve data
• POST – Submit form data / upload
• PUT – Update entire resource
• PATCH – Partial update
• DELETE – Remove resource
• HEAD – Only metadata

✔ HTTP Request Example

GET /index.html HTTP/1.1
Host: www.example.com
User-Agent: Chrome

✔ HTTP Response Example

HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 4520

3️⃣ HTTP Status Codes

4️⃣ HTTPS (HyperText Transfer Protocol Secure)

HTTPS is the secure version of HTTP, using TLS (Transport Layer Security) or SSL encryption. It protects data transmitted between browser and server.

✔ Features of HTTPS

• Runs on port 443
• Data is encrypted
• Provides authentication
• Prevents eavesdropping & MITM attacks

✔ TLS Security Benefits

• Confidentiality – Data encrypted via AES
• Integrity – HMAC verifies no tampering
• Authentication – Server identity verified using certificate

5️⃣ HTTPS: TLS Handshake Process

The TLS handshake securely establishes encryption keys.

✔ Steps (Explained in Words)

1. Browser sends "Client Hello"
2. Server responds with certificate
3. Browser verifies certificate
4. Browser generates session key & encrypts it
5. Server decrypts and establishes secure session

✔ After Handshake

All communication becomes encrypted using symmetric keys.

6️⃣ HTTP vs HTTPS

7️⃣ Real-world Examples

✔ E-commerce

Amazons checkout uses HTTPS for secure payments.

✔ Banking

All banks use HTTPS to protect user credentials.

✔ Social Media

Facebook, Instagram encrypt messages & logins using HTTPS.

📝 Conclusion

WWW provides the world’s largest collection of online content, while HTTP enables its communication and HTTPS secures it. Understanding HTTP and HTTPS is essential for web development, cybersecurity, and network engineering.