Customized reports are good for defining reports whose content does not change. A customized report is also the only way to create a report that contains data for different time periods in the same report.
Customize reports are designed just like report templates, but are bound to specific groups, assets and monitors. For that reason customized reports are not run by first selecting a node in the monitor tree. Instead you both create and run customized reports by selecting Network Monitor > Reports > Customized reports.
Note: Since the design and running of customized reports are so similar to report templates, you should familiarize yourself with configuring report templates first. Customized reports simply provide additional fields that require you to specify groups, assets and monitors.