Client Issues A Request And Server Sends A Response

As seen earlier, each web server controls a website from amongst the collection of several web pages (i.e, the website), one page is treated as a "Default Web Development".

When a Browser connects to a Web Server using an appropriate protocol name, IP address and port number, and the Web Server treat this connection to be a request for the 'Default Web Document'. The Web Server then dispatches the 'Default Web Document' to the client who connected.

if the client requires viewing any other web pages then the client can specify the web page name (if known) along with the connection information. Thus the complete connection and web page information will now be specified as 

protocol://servername:port number/web page name.

A webpage, apart from the text and HTML tags, can also include references to external objects like GIF's, JPG's, Audio files, Video files and so on.

Thus the request for a webpage can be two-fold:

• The webpage itself
• The request for the object referenced by the web page i.e. GIF's, JPG's, Audio file, Video files, executable programs and so on. 

When an appropriately structured, HTTP request is received from a Browser, the web server will try ti locate the web page requested. If the web page exists, the server responds by providing the page to the browser,

if the webpage is not found, an appropriate 'Error Message' is sent as response to the browser request. After sending the web page the web server resets the connection with the browser.

After receiving the web page, the browser will identify the external objects that specified in the web page (if any) and request the server to deliver the external objects.

Such a request will result in a connection being re-established with the web server and a request being sent by the browser. The web server responds to the request being sent by browser.

Understanding How A Web Browser Communicates with A Web Server