CIFS – Common Internet File System, pronounced ‘sifs’. This is a Windows filesystem SMB (Server Message Block) dialect. The CIFS implementation of SMB is rarely used these days and most modern storage systems use SMB 2 or SMB 3. CIFS gained a reputation for problematic client/server interactions, proprietary extensions, and poor performance over high latency networks. Because of this Microsoft comprehensively re-engineered it, effectively replacing it with the faster-performing SMB 2 in Windows Vista in 2006 and then SMB 3 in Windows 8 and Windows Server 2012.