Definition of: NetBIOS
The original networking protocol for DOS and Windows PCs. NetBIOS packets did not contain a network address and were not easily routable between networks. As a result, the interface to NetBIOS and the transport part of NetBIOS were later separated so that NetBIOS applications could use routable protocols such as TCP/IP and SPX/IPX. The programming interface (API) retained the NetBIOS name, while the transport protocol was renamed NetBEUI (pronounced "net-boo
Today, NetBIOS is used to support legacy NetBIOS applications but is also widely used for NetBIOS name resolution. Since NetBIOS was the first major standard for PC networks, computers were named according to the NetBIOS format, which identifies a machine by a unique 15-character name. NetBIOS machines periodically broadcast their names over the network so that Network Neighborhood or My Network Places can catalog them.
Datagram and Session Modes
NetBIOS is generally defined as a session layer protocol in the protocol stack, supporting two modes: a fast Datagram mode that does not guarantee delivery and a Session mode that establishes a connection and guarantees delivery. See NetBIOS over TCP/IP
and LMHOSTS file