XForms: where the form data is saved

     I am new to XForms. I created the questionnaire form with Form Builder and published the form. After saving the form data I am not able find the data entered in the form. Please let me know where the data will be saved and format of the data being saved.
Please let me know whether it will saved in xml format or in database. If it is storing in database where I can find the code which writes to the database. I also want the option of how to data to the database.

please reply back. thanks in davance