Server Message Block. SMB is a message format used by DOS and Windows to share files, directories and devices. NetBIOS is based on the SMB format, and many network products use SMB. These SMB-based networks include LAN Manager, Windows for Workgroups, Windows NT, and LAN Server. There are also a number of products that use SMB to enable file sharing among different operating system platforms. A product called Samba, for example, enables UNIX and Windows machines to share directories and files.
This is a client-server method of communication that allows a client to make requests for resources over a network. A server responds to these requests. SMB runs over most common network protocols, including NetBEUI, IPX/SPX and TCP/IP.