Definition
NVMe is a communication protocol optimized for low-latency access to non-volatile storage devices, especially SSDs attached through PCI Express.
How it works
It supports parallel submission and completion queues that can make effective use of multicore processors. The protocol is separate from physical form factor: an M.2 device may be NVMe or SATA. NVMe over Fabrics also enables networked deployments.
Real-world example
A server with many random I/O operations may benefit from NVMe rather than SATA SSDs when applications, CPU and other storage layers do not become the bottleneck.
Limits and best practices
Monitor temperature, write endurance, media errors, firmware and power-loss protection when needed. Low latency does not replace appropriate redundancy, recovery planning or tested backups.