A monitor report represents a detailed view of the files that have changed, deleted or added inside your monitor.
Each time when the cron jobs will run, they will create reports for all your monitors and inside these reports you can view valuable info, for example this is an overview with all the reports for a certain monitor, in this case a monitor for wordpress:
Looking inside a report, we can see filtered info about what exactly changed:
But even more, we can see how it changed:
As you can see, monitor reports will give you very detailed reports about the files that you monitor.