CBSE 12th CS Unit - 2 Chapter 7 - INTRODUCTION TO WEB SERVICES

                                                                    TOPIC – 7

                                                  INTRODUCTION TO WEB SERVICES

1. WWW (World Wide Web)

• The WWW is a system of interlinked hypertext documents accessed via the Internet.
• It's a vast collection of websites, web pages, and other resources that can be accessed through a web browser.
• The WWW is not the same as the Internet, but rather a service that runs on top of it.

2. Hyper Text Markup Language (HTML)

• The standard markup language for creating web pages.
• Uses tags to structure content, such as headings, paragraphs, images, and links.
• Tells the web browser how to display the content on the screen.
• Example: <h1>This is a heading</h1>

3. Extensible Markup Language (XML)

• A markup language similar to HTML, but designed to store and transport data.
• More flexible than HTML, allowing for custom tags to be defined.
• Used for data exchange between different systems.
• Example:

XML

<?xml version="1.0"?>

<books>

  <book>

    <title>The Lord of the Rings</title>

    <author>J.R.R. Tolkien</author>

  </book>

</books>

4. Domain Names

• Human-readable names for internet addresses (IP addresses).
• Examples: [invalid URL removed], facebook.com, example.edu
• Make it easier to remember and type website addresses.

5. URL (Uniform Resource Locator)

• The address of a specific web page or resource on the internet.
• Typically starts with "http://" or "https://" followed by the domain name and a path to the specific resource.
• Example: [invalid URL removed]

6. Website

• A collection of web pages and related resources hosted on a web server.
• Can be accessed through a web browser by typing the website's URL.

7. Web Browser

• Software application used to access and display web pages.
• Examples: Google Chrome, Mozilla Firefox, Microsoft Edge.

8. Web Servers

• Powerful computers that store and deliver web pages and other resources to web browsers.
• Run special software called web server software (e.g., Apache, Nginx).

9. Web Hosting

• The service of providing space on a web server for storing and accessing website files.
• Web hosting companies provide the necessary hardware, software, and internet connectivity.

Diagram: How a Web Page is Accessed

[Image of a diagram showing the process of accessing a web page:

1. User types URL in web browser.
2. Browser sends request to DNS server.
3. DNS server translates domain name to IP address.
4. Browser sends request to web server.
5. Web server retrieves requested page.
6. Web server sends page to browser.
7. Browser displays the web page.]

Simple Terms

• Imagine the internet as a giant library.
• HTML: The language used to write the books in the library.
• XML: A special language to organize and share information within the library.
• Domain Name: The name of the library (e.g., "City Library").
• URL: The specific address of a book within the library.
• Website: A collection of books and other resources within the library.
• Web Browser: Your tool for reading the books.
• Web Server: The librarian who helps you find the books.
• Web Hosting: The library building itself.