: This part of the filename indicates that it is a Cisco NX-OS software image. NX-OS is the operating system used on Cisco's Nexus series of switches.
: It is used for physical switches like the N3K-C3048TP and virtual environments like the Nexus 9000v (used for lab testing on laptops). Why This Specific Version? Nxos.7.0.3.i7.6.bin
For detailed release notes, hardware compatibility lists, and security fixes included in this release, refer to the official Cisco Nexus 9000 Series NX-OS Release Notes. : This part of the filename indicates that