Persistent memory (PMEM) is a new technology that adds a storage layer between Solid State Drives (SSDs) and Dynamic Random Access Memory (DRAM), and takes the best of both technologies. Recall that SSDs are devices that store data in dense, non-volatile, Flash memory and are much faster than spinning hard drives that store data on magnetic disks. DRAM is typical server memory, which is very fast but is volatile, meaning that data is only stored when power is applied. When power is lost, the data in DRAM is lost as well. PMEM, also referred to as a Non-Volatile Dual Inline Memory Module (NVDIMM), is a technology that is as fast as DRAM, hundreds of times faster than SSDs, but non-volatile, like SSDs, and provides a useful function in a vSphere environment. VMs don't even have to be PMEM-aware. Legacy applications and operating systems can utilize PMEM technology in vSphere 6.7. PMEM-based storage can be presented as a virtual disk to legacy operating systems or directly to PMEM-aware operating systems.