Need help understanding backup of Hyper-V VMs

Hi, I need help understanding the backup process for our VMs that reside inside a Clustered Shared Volumen.

When I look at the Backup selection list I see the volumes and the folders that represent the individual VMs.

But I also see a list of all the virtual servers listed under 'Microsoft Hyper-V HA Virtual Machines.

Do I need to check these boxes aswell? What does it do that is different to backing up the folders within the clustered volumes? Is it perhaps for GRT purposes?

Should I be checking these boxes instead of the volumes?

thanks in advance.