The steps involved in transmitting form data from the client to the web server

1. User loads web form
2. User enters data in to web form fields
3. User clicks submit
4. On submit page validates fields using JavaScript. If validation errors are found then the validation script stops the browser from canceling posting the data to the web server and displays error messages as needed
5. If the form passes the data validation process then the browser will URL encode the values of every field and post it to the server. 
6. The server reads the posted data from the query string and then again validates the data just to ensure data consistency and to prevent any non-validated data because JavaScript was turned off on the clients browser from being inserted in to a database or passed on to other process
7. If the data passes the second validation check then the server side code will continue with the requested processes