UNIT I WEBSITE BASICS, HTML 5, CSS 3, WEB 2.0

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  2.1 Web Essentials: Clients, Servers and Communication 


Client-Server Model:

                       The Client-Server Model is a distributed architecture where clients request services and servers provide them. It underpins many modern systems, including websites, email, and cloud storage platforms.
 

Client: A client is any device or software that initiates communication by requesting data or services from a server. Common client applications include:

Web browsers (e.g., Chrome, Firefox)

Email apps (e.g., Gmail, Outlook)

Server: A server is a powerful systems that listens for and responds to client requests by delivering data or performing tasks. Servers often handle multiple simultaneous client requests. Common server applications include:

  • Web Servers (e.g., Apache, Nginx)
  • Email Servers
  • Database servers
Client-Server-Model
Client Server Model

How the Browser Interacts With the Servers?

The process of interacting with servers through a browser involves several steps:

1. User Enters the URL (Uniform Resource Locator):
The user types a website address (e.g., www.example.com) into the browser's address bar.

2. DNS (Domain Name System) Lookup:
The browser contacts a DNS server to convert the domain into an IP address.

3. Establishing a Connection:
The browser sends an HTTP/HTTPS request to the server using the resolved IP address.

4. Server Responds:
The server sends back website files (HTML, CSS, JavaScript, images).

5. Browser Renders the Webpage

  • DOM interpreter: Processes HTML to structure the page.
  • CSS interpreter: Applies styles
  • JavaScript Engine: Adds interactivity (using JIT compilation for performance).
Client-Server-Model
Client Server Request and Response

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