The NIC (Network Interface Controller) is a network adapter or LAN adapter that connects a computer to a computer network. The NIC operates on both the physical and data link layers of the machine and allows network connectivity. All virtualization hosts in a Red Hat Virtualization environment have at least one NIC, though it is more common for a host to have two or more NICs.
One physical NIC can have multiple Virtual NICs (VNICs) logically connected to it. A virtual NIC acts as a physical network interface for a virtual machine. To distinguish between a VNIC and the NIC that supports it, the Red Hat Virtualization Manager assigns each VNIC a unique MAC address.