How can I allow users to edit the data in a submission?

I want to allow users to search for a previous submission and make edits. Is this possible?

Yes, that's possible. Just provide them their edit URL.

https://www.jotform.com/edit/SubmissionID

Where SubmissionID is there actual submission ID.

To get the Submission ID, just go to your form's submissions page

You can also make it automatic by adding the edit link in the autoresponder message.

https://www.jotform.com/help/40-How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date