It’s a communication interface, which has been created particularly for the SSDs (Solid State Drives) by a group of SSD manufacturers. NVMe is an optimized, scalable, and high-performance host controller interface with a proficient register interface and command set built to access the SSDs attached via the PCIe (Peripheral Component Interconnect Express) bus. Since the PCIe bus supports thousands of parallel command queues, it’s much faster compared to hard disks and conventional all-flash architectures that deal with a solitary command queue. To put it more simply, NVMe drives allow the SSDs to communicate over the PCIe connector to expand their capabilities.