The Fujitsu Memory Riser Board S26361-F5295-L200 is a server component for adding memory capacity in compatible Primergy systems. It provides 12 slots for DDR4 RAM, giving the server additional positions for memory modules.
The listed compatible systems are Primergy RX4770 M2 and RX4770 M3. This board is intended for those server models, so its role is specific: it expands the available memory slots within a supported configuration.