What is an architectural framework created by ETSI that defines standards to decouple network functions from proprietary hardware-based appliances and have them run in software on standard x86…

NPIV (N_Port ID Virtualization) is a Fibre Channel SAN feature that allows a single physical HBA port to present multiple virtual ports, used in storage networking and entirely unrelated to network function virtualization.

NFVIS (NFV Infrastructure Software) is a Cisco-proprietary platform product that implements NFV infrastructure capabilities on Cisco ENCS hardware, making it a vendor-specific implementation rather than the overarching ETSI architectural standard.

Network Functions Virtualization (NFV) is an architectural framework standardized by ETSI that separates software-defined network functions - such as firewalls, load balancers, and WAN optimizers - from the proprietary, purpose-built appliances that traditionally hosted them. By running these functions as software instances on commodity x86 hardware, NFV enables rapid service deployment, elastic scaling, and significant reductions in capital and operational expenditure. NFV defines a layered architecture that includes the NFV Infrastructure (NFVI), the management and orchestration layer (MANO), and the Virtual Network Functions (VNFs) themselves.

A VNF (Virtual Network Function) is the individual software instance of a virtualized network service - such as a virtual router or virtual firewall - that runs within the NFV framework, making it an artifact produced by the NFV architecture rather than the framework itself.