NetBIOS is now supported on Ethernet, TokenRing, and IBM PC Networks. In its original form, it was defined as only an interface between the application and the network adapter. In a NetBIOS LAN environment, computers are known on the network by a name. Each computer on the network has a permanent name that is programmed in various different ways. These names will be discussed in more detail below.
Sessions allow larger messages to be sent, and handle error detection and correction.
Datagram and broadcast methods allow one computer to communicate with several other computers at the same time, but are limited in message size. There is no error detection or correction using datagram or broadcast methods. However, datagram communication allows for communication without having to establish a session. The allocation of these blocks in memory is dependent on the user program. These NCB's are divided into fields that are reserved for input and output respectively.