The Quick Reports section on the top of the page, lists a few quick links for more commonly used reports, such as the "Priority/Status" report which groups issues by status within each priority value.

The Custom Reports section allows the user to be creative and choose any fields for the reports.

Note:

The filters can sometimes cause problems for users if they forget that a filter is active. If you are missing information about specific issues in your output, it is probably because a filter is set. If a filter is active, you will notice its definition at the top of the page.