RAID & File System Group
The RAID & File System group contains settings pertaining to the operation mode of the internal HDDs. You do this on the RAID Management page while the File System Management page is just more detailed about the created partitions. The NS2300N offers quite advanced RAID-related features, by the way. It supports hot swapping and installation of HDDs and you can migrate from one type of RAID to another without data loss in some cases.
The EzBackup page of the Backup group enables quick backup mode available in the SmartNAVI program.
The Network group contains but one page called Network Setup. The parameters of the network interface of the NS2300N are specified here.