The SMB protocol is a high-level specification for formatting messages to be sent
across the network and correlates to the application layer (Layer 7), and the presentation
layer (Layer 6) of the OSI model described in Chapter 9.
An API called NetBIOSis used to pass I/O requests structured in the SMB format to a remote computer.
Both the SMB protocols and the NetBIOS API were adopted in several networking products
before appearing in Windows