NetBIOS
The Network Basic Input/Output System is a network protocol for PC local area
networks. NetBIOS is commonly used within a network segment or corporation, but
cannot be transmitted across a router without the use of another protocol. NetBIOS addresses are typically the
computer name, thereby simplifying the networking details and addressing from the
users.
NetBIOS provides session and transport services (layers 4 and 5 of the OSI model), but does not provide a standard format for transmission over the network.
Different implementations of NetBIOS were later formalized into NetBEUI, which
is used in all Windows operating systems that support networking.