Server Message Block (SMB) is a network file sharing protocol. SMB allows users to read and write files over a local area network (LAN).
The Common Internet File System is a dialect of SMB, a dialect is the set of message packets that define a particular version of the protocol. In simpler terms, CIFS is a particular version of SMB.
Today SMB is the way to go. CIFS is rarely used in modern storage systems which lean on SMB 2 or SMB 3 which have made vast improvements over the CIFS protocol.