TCP/IP, the lingua franca of the Internet, was developed on UNIX systems. As such, Linux has benefited from this heritage by naturally fitting in to any TCP/IP network. Yet, sometimes you still need to deal with computers whose operating system has distinctly non-TCP/IP legacy networking components. A case in point is sharing your printer to Windows users.
And this is something reasonable to do; sharing a single printer among all the computers in your household or workplace – irrespective of their operating system – can save money and add convenience. Although Microsoft made TCP/IP the standard network protocol from Windows 2000 on, its Windows operating systems still use a proprietary protocol – SMB, or Server Message Block – to communicate amongst its sibling systems. (TCP/IP stacks were available right back to Windows 3.1 and DOS, but these were not the default protocol until Microsoft made TCP/IP a fundamental part of Active Directory.)
http://www.linuxlinks.com/portal/news/article.php?story=20071024140242918