The query studio is used to create adhoc reports, it is easy to understand the bussiness user.The report studio is mainly used to create proffessional and corporate reports, it is not like query studio it is having mainly 3 explorers those are page explorer,conditional explorer and variable explorer by using these it is working.

You can view the output in the work area itself while creating the reports in QS but in report studio only when u run the report you can view the values ie the output.