• The Internet: A global network of interconnected computers and hardware. It serves as the physical infrastructure (wires, satellites, routers) that allows data to travel globally.
• World Wide Web (WWW): A service or software layer that runs on top of the Internet. It is a collection of documents (webpages) connected by hyperlinks and URLs.
• Difference between Webpage and Website:
  • Webpage: A single document written in HTML (like a single page in a book).
  • Website: A collection of related webpages linked together under a unique domain name (like the whole book).
• URL Structure (Uniform Resource Locator): ```
  • Protocol: Usually http:// or https://. It defines how data is sent.
  • Domain Name: The human-readable address (e.g., google.com) that points to a specific server.
  • Path: The specific location of a file or folder on that server (e.g., /about.html).
  ```
• Web Browsers:
  • Browsers are software applications (like Chrome, Firefox, Safari, Edge) used to access the WWW.
  • Function: They request files from servers and render (translate) HTML/CSS code into a visual format that humans can read.
• How they work with HTML:
  • The Browser acts as the client.
  • The Internet acts as the highway.
  • The Server stores the HTML files.
  • When you enter a URL, the browser fetches the HTML from the server and displays the Webpage.

<!-- Example of a URL Breakdown -->
Protocol: https://
Domain:   [www.sswebtechio.com/](https://www.sswebtechio.com/)
Path:     /products/index.html
Full URL: [https://www.sswebtechio.com/view-chapters.php?course=10](https://www.google.com/search?q=https://www.sswebtechio.com/view-chapters.php?course=10)

• The Client-Server Model: This is the basic communication structure of the internet where two computers talk to each other to deliver a webpage.
• The Client:
  • This is your device (computer, phone, or tablet) and the Web Browser (Chrome, Safari, etc.).
  • It is called the "client" because it requests services or files.
• The Server:
  • A powerful computer that stays on 24/7 and "serves" data.
  • It stores the HTML, CSS, and Image files of a website.
  • When a request comes in, it finds the file and sends it back.
• The Process (The Request-Response Cycle):
  • Request: You click a link or type a URL. Your browser sends a message across the internet asking for a specific HTML file.
  • Response: The server receives the message, locates the file, and sends it back to your browser.
• Real-world Analogy:
  • Client: A customer at a restaurant (ordering food).
  • Server: The waiter (taking the order to the kitchen and bringing the food back).
  • Internet: The floor of the restaurant where the waiter walks.

<!-- Simplified Communication --> Client: "Hey Server, please send me 'index.html'." Server: "Checking... Found it! Here is the code." Browser: (Receives code and displays the website)

• Front End (Client-Side):
  • Everything the user sees and interacts with in the browser.
  • Focuses on user interface (UI) and user experience (UX).
  • Main technologies: HTML (structure), CSS (design), and JavaScript (interactivity).
• Back End (Server-Side):
  • The "behind-the-scenes" part that the user cannot see.
  • Focuses on databases, server logic, and application processing.
  • It handles things like logging in, processing payments, and storing user data.
• Client and Server Scripting Languages:
  • Client-Side Scripting: Code that runs directly in the user's browser. The most common language is JavaScript.
  • Server-Side Scripting: Code that runs on the web server before the page is sent to the user. Common languages include PHP, Python, Node.js, and Ruby.
• Responsive Web Designing:
  • An approach where a website "responds" or adjusts its layout based on the device's screen size.
  • Ensures the website looks good and is easy to use on desktops, tablets, and mobile phones.
  • Uses flexible grids, layouts, and CSS media queries.
• Types of Websites: Static vs. Dynamic:
  • Static Websites:
    • The content is fixed and stays the same for every visitor.
    • Built mainly with HTML and CSS.
    • Fast to load but difficult to update manually for many pages.
  • Dynamic Websites:
    • The content changes based on user interaction, time, or database information (e.g., Facebook, Amazon).
    • Uses Server-Side scripting and databases to generate pages on the fly.
    • Easier to manage large amounts of content.

<!-- Front End vs Back End Summary --> Front End: HTML, CSS, JS -> "The Look" Back End: PHP, Python, SQL -> "The Brains" Result: A complete, functional Web Application