Question on the Upload Document storage

Where are the documents uploaded by clients stored? Are the documents secure? Do users have the option to upload their documents directly to another s

We follow the best security practices when it comes to handling customer data. You can learn about our security practices at - https://www.jotform.com/security 

We use Amazon Storage Services for saving the uploaded files the submissions details and notification email includes a link to the uploaded file.

You typed your question in the thread title instead of description hence some part of your question was cropped. I am not sure what your last question was. 

If it's related to saving files on external storages. Then the answer is Yes, it's possible. You can upload files to DropBox or use your own FTP server.

You can go the Submission Page of your forms and edit settings to send uploads to your FTP as shown below - 

I hope this helps. Let us know should you need further assistance.