How does the user submit a completed form?

You have to add a submit button on the form. Users can submit the form by clicking on this submit button and the submissions are recorded in our server. You could see these submissions  in the submission view:

https://www.jotform.com/help/269-How-to-View-Form-Submissions

https://www.jotform.com/help/46-Quick-Overview-of-Form-Fields

Let us know if you have further questions.

Thanks.