What is Common Internet File System / Server Message Block (CIFS SMB)?
Common Internet File System / Server Message Block is a protocol for sharing files, services and resources over a network.
It was developed by Microsoft and is a variation on the older SMB protocol.
It is designed for use over a wired low-latency network because its high operational communication overhead would produce noticeable performance degradation if used over a high-latency WAN network like the Internet. This protocol operates at the application or presentation layer of the OSI networking model.