Web Browser’s Role

client is an application that runs on a personal computer and relies on a server to perform operations.In our case web browser is the client to access web pages resides on the web server.
web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web.
Their role is relatively simple:

1. Send requests to the web server.
If the user enters http://www.dotnetcypher.com, the web browser resolves the www.dotnetcypher.com Domain Name System (DNS) address, uses HTTP to connect to the server, and requests a page.
2. Authenticate the server.
If the server has an SSL certificate and the request was made with HTTPS, the web browser uses the certificate to authenticate the server and then decrypt future communications.
3. Process the response.
If the server has provided HTML, the browser retrieves embedded objects, such as images, videos, or animations referenced in the HTML. If the server has provided an error, redirection, or other response, the browser responds appropriately.
4. Display HTML and embedded objects.
Web browsers use HTML standards to determine how to display a webpage to the user. Because HTML can contain embedded objects, a web browser might have to display dozens of objects to render a single webpage.
5. Run client scripts.
Client scripts, such as those written in JavaScript, enable interactive and responsive pages without reloading the page.

Here are the more links.

http://www.allaboutcookies.org/browsers/index.html
http://create-website.org/concepts/webbrowser.html

Understanding Web Communications

Like all client-server applications, web applications have two distinct components:
Client Also known as the front-end interface, the web browser presents the user interface, accepts user input, and sends data to the server for processing.
Server Also known as the back end, the web server responds to requests from clients for specific pages. It responds with an HTML page that includes instructions for how to generate the user interface.

The web browser (the client) and the web server communicate by using Hypertext Transfer Protocol (HTTP), a text-based network protocol assigned to TCP port 80. If the server has a certificate, the client and server can use HTTP Secure (HTTPS) to authenticate the server and encrypt communications. HTTPS is assigned to TCP port 443.

Communications typically follow these steps:
1. A user enters an address, such as http://www.dotnetcypher.com/, into the web browser.
2. The web browser connects by using HTTP and sends a GET request, such as GET / (to retrieve the root page), to the web server.
3. The web server processes the requested page. This action might cause the server to return static HTML or image files, or it might execute application code(ASP.NET code) that performs workflow tasks or connects to a database.
4. The web server uses HTTP to send a response back to the web browser. If the request was processed successfully, the web server returns the HTTP status code 200, along with an HTML document. If the server cannot find the page, it returns the code 404. If the user requests an outdated or relocated page, the server returns the code 302 and the new URL so that the browser can access the correct page. This is known as redirection. Several other responses are possible as well, depending on the particular situation.
5. The user’s web browser then processes the response by displaying the HTML page (if the code was 200), showing an error message (if the code was 404), or loading a different page (if the code was 302). Other server responses are similarly handled by the browser, depending upon the response.

This process is repeated each time the user clicks a button or link(any of post back behavior control).