Forms and Form Data

State Information Overview

• We have established that it is possible for a web browser (client) to send data to a web server, but there is another problem to be solved for effective use of form data.
• Picture an online store, where users keep adding items to their shopping cart while browsing your site, then eventually want to check out and supply payment and shipping information.
• Each browser (client) request for a page is a brand new and completely unique request to the web server. But, the server must somehow keep track of where each customer has been and what they have added to their cart.
• Also, thousands of different people are simultaneously browsing your site... you have to keep track of who has what in their shopping cart without getting them confused with each other.
• This information about what a user has done, what they have accumulated, and where they have been, is a type of state data.
• Actually, there are at least three common ways to accomplish this, POST data, GET data, and cookies.