Definition: SMB

(1) (Small to Medium-sized Business) Also called small to medium-sized enterprise (SME), SMBs are companies with approximately 25 to 500 employees. However, some SMB/SME ranges use an upper limit of 5,000. From an IT viewpoint, SMB/SME designations mean the number of workstations that must be managed. See SOHO.

(2) (Server Message Block) The file sharing protocol in DOS and Windows. In the 1990s, Microsoft renamed SMB to "Common Internet File System" (CIFS), and it is often referred to as SMB/CIFS. Mac and Linux computers also use SMB/CIFS to access shared folders on Windows machines and vice versa.

SMB originated with the NetBIOS protocol used in the first DOS networks and later migrated to OS/2 and Windows. See CIFS, file sharing protocol and Samba.

SMB Means Network Shares

In mixed-platform networks, users may run across the term SMB. This example is the file manager from the KDE user interface on a Linux computer. The "SMB Shares" icon represents all the shared files and folders on the Windows computers in the network.

From Mac to Windows

This Mac dialog was displayed when trying to connect from the Mac to a Windows machine on the network. The SMB/CIFS nomenclature was later dropped in Mac OS X 10.5 (Leopard) to hide the jargon.