Some applications cannot be completed by the user in one session. If your application is very large or complicated, you can allow users to save their work as a draft before submitting it.
In any stage, you can enable authenticated users to save their work as a draft. When a user returns to a saved draft in a form, a message asks whether to start a new form, or continue working on the draft. You can add an option for users to email themselves a link to their own draft. A user can save one draft on any stage at any time. The draft is also reflected in View Responses.