The term Network Interface(NI) can have different meanings in different applications.
For example, a network interface can be the interface between the user terminal and a private or public network. Or it may be an interface to a switched network with circuit switching or with data packet switching. It can be the interface from a network interface card( NIC) in a personal computer, or the interface between different networks with the same or different switching methods. Furthermore, there are network interfaces between access networks and core networks or between wired, optical or radio-based WLANs.