Where do the data of a created jotform be stored at? How can one retrieve those data for business use and for analysis?

The data i.e. the form response or submissions are stored in your JotForm account itself.

It can be accessed from the Form Submission page or JotForm Inbox.

You can download the form submissions as PDF, Excel or CSV: How-to-Download-Form-Submissions-as-Excel-CSV-PDF 

OR

You can created reports based on the submissions received: How-to-Create-Form-Reports-in-JotForm

Hope this helps.