This is a general summary report of the tickets that users have submitted in a date interval. Specify the date interval in a YYYY-MM-DD format, select a category and the report will show the corresponding tickets.
By default the From and To fields' contents is set to the last two weeks.
"Time spent" represents the time spent by a technician on the ticket. It is the "time spent" field that is present in every ticket. You can see the automatic "stopwatch" counter whenever you open a ticket in the web-app. You can also edit this field manually if the automatic tracker doesn't work for you.
"Response time" is the time between a ticket has been created and the "start time" (when the ticket has been taken by a technician).
"Duration" is the time between ticket creation and ticket being closed/resolved.
Read more on other reports in the help desk app.