Summary: Below explains how the Satisfaction Survey works.
After a ticket has been closed, if the user reviews the detail page for that ticket, they will be presented with a chance to provide a feedback score from 1-5 indicating their level of satisfaction with the resolution of this ticket. They are also able to add additional comments to this.
These values get stored in the ticket and are not editable by the help desk admin.
There are a variety of reports displaying this information. See the Help Desk category for the complete list.
Additionally, on the main Help Desk configuration page there is a check box that indicates if the submitter of a ticket should get an email when the ticket moves into a closed state asking them to take the survey. In that mail is a link to the ticket, allowing the user to quickly respond to the request.
NOTE: In Version 5.3 the Satisfaction Survey check box has been changed to Ticket Closed