A Non-Volatile Dual In-line Memory Module (NVDIMM) is a computer memory RAM DIMM that retains data even when electrical power is removed either from an unexpected power loss, system crash or from a normal system shutdown. NVDIMMs can be used to improve application performance,[1] data security, system crash recovery time and to enhance SSD endurance and reliability.
There are two main types of NVDIMM cards: NVDIMM-F and NVDIMM-N.
NVDIMM-F is a Flash-only device that resides on the memory interconnect.
NVDIMM-N is a byte-addressable memory-mapped device, which is typically accessed at memory or near-memory speeds. DDR4 NVDIMM-N cards are being sold by multiple hardware vendors and support is getting wider.[4][non-primary source needed] These NVDIMM-N devices utilize DRAM for performance and endurance, though are limited in capacity and result in higher costs due to the use of both DRAM and flash memory.
References: https://en.wikipedia.org/wiki/NVDIMM