FSD - File System Driver: A Driver that implements a File System
FCB - File Control Block: Uniquely represents an open, on-disk object in system memory. (a similarity to vnodes in UNIX). When an object is successfully opened in the Object Manager, an FCB is created by the IO Manager.
CCB - Context Control Block: A CCB is created by the FSD when a successful open operation in made by a user mode program. A Handle is returned and the CCB is a kernel representation of this handle.