In order to answer this question first lets understand how does browser and server work when we request any website. Below figure depicts pictorially the web environment. When client sends data to the server it post backs form element data, hidden fields,images,cookie information to the server and server make the page and sends the same information back to the browser. The bad part this happens with every request and response.

Below are the issues with the above model:-

Unnecessary data transfers: – In the above model unnecessary data is transferred between client and server. For instance the whole page is posted and More >