The main dashboard of the Reports area displays a birds-eye view of all of the issues (vulnerabilities and licenses) found across all of your projects, presenting data for these specific areas:
Your overall project activity—a summary of all of your projects, tests and issues
Data in each of the four tabs is displayed based on the filters you've applied from the top of the Reports area, as well as the group or organization that you're viewing from.
The dashboard appears similar to the following image:
To quickly view additional data for a specific period in time, hover over the relevant graph and check out the pop-up: