Groups tab in report, what is the purpose

[test.0...@gmail.com]

Hello Galen Folks,

I'm curious, what is the groups tab for in the report? http://galenframework.com/public/samples/reports/report.html#groups 

I'd like to step my report game up a notch, wondering if I could use the groups tab somehow. 

Thanks! 

Cory 

PS: thanks for creating and maintaining (and open sourcing) and awesome testing tool!