World Wide Web:

• The World Wide Web (WWW) is a distributed system that enables users to access and share information over the internet. 
• It is a vast network of interconnected hypertext documents that are identified by Uniform Resource Locators (URLs) and can be accessed using a web browser.
• The WWW uses a client-server model where web servers store and serve web pages and other resources to client browsers upon request. 
• One of the key features of the WWW is its decentralized nature, with no central control or ownership. 
• This allows for widespread collaboration and the ability for anyone to publish and access information online.
• However, this also presents challenges such as ensuring the reliability, security, and accessibility of web resources.

 

Components of WWW

Web Browsers: 

• A web browser is software that is used to access and display web pages. 
• Examples of popular web browsers include Google Chrome, Mozilla Firefox, and Microsoft Edge.

 

Web server:

• A web server is a software application that handles HTTP requests sent by clients and responds with the requested resources, such as HTML documents, images, videos, and other files. 
• It is the primary component of the World Wide Web architecture and acts as a mediator between the client and the web application.

 

Web Applications: 

• Web applications are software programs that run on web servers and provide interactive functionality to users. 
• Examples of web applications include online shopping websites, social media platforms, and email clients.

 

Hypertext Markup Language (HTML):

• HTML is a standard markup language that is used for creating web pages.
• It defines the structure and content of web pages using a series of tags and attributes.
• It is the foundation of the World Wide Web and is used to create most of the web pages on the Internet.
• You don't see HTML tags when you open a webpage as browsers don't display the tags and use them only to render the content of a web page. 
• In simple words, HTML is used to display text, images, and other resources through a Web browser.

 

HTTP:

• HTTP stands for Hypertext Transfer Protocol, which is a protocol used for communication between web servers and web browsers. 
• It is the foundation of data communication for the World Wide Web.
• HTTP is a ‘request-reply’ or ‘client-server’ protocol. 
• HTTP defines a small set of operations or methods that can be performed on a resource. 
• The most common are GET, to retrieve data from the resource, and POST, to provide data to the resource.

 

URL:

• URL stands for Uniform Resource Locator
• It is a string of characters used to specify the location of a resource on the internet. 
• In other words, it is a web address that uniquely identifies a resource on the internet.
• A URL consists of 4 parts, including the protocol, domain name or IP address, port number (optional), and path.

 

 

• The protocol is the method used to access the resource, such as HTTP or HTTPS. 
• The domain name or IP address specifies the location of the server hosting the resource. 
• The path specifies the location of the resource on the server.
• For example, in the URL "https://www.example.com/index.html", the protocol is HTTPS, the domain name is "www.example.com", the path is "/index.html".

 

Working of WWW

                       

• The client sends a request message to the server containing the URL of the required resource. 
• The server looks up the path name and, if it exists, sends back the resource’s content in a reply message to the client. 
• Otherwise, it sends back an error response such as the familiar ‘404 Not Found’.