LOUIEANN, hello! The term "kernel" is used in many different ways. A very general definition would be that it is the core components of the operating system. Everything that sits above the hardware, doing hardware abstraction, and below the software, providing system service APIs could be considered the kernel. Different OS makers define kernel in different ways. For example, the term microkernel is used to denote a small, stripped-down kernel that leaves out most of the system and application services. Windows 7 uses a hybrid kernel. You can read more about the use of the term kernel at Wikipedia:
Microsoft is happy to tell everyone what is new in Windows 7 which, by the way, has not shipped yet.
Blackcomb and Vienna are both internal Microsoft code names for the product that is now called Windows 7. There may be a distinction of importance to Microsoft employees, but the rest of us should just say Windows 7.