(Common Internet File System) The file sharing protocol used in Windows. It evolved out of the SMB (Server Message Block) protocol in DOS, which is why the terms CIFS/SMB and SMB/CIFS are commonly used. The word "Internet" in CIFS does not refer to the global Internet but to generic internetworking. The term was coined in the 1996 time frame when Microsoft submitted CIFS to the IETF and before the global Internet had become mainstream. See file sharing protocol, SMB and Samba.