This is a tutorial and demonstration of the basics of the Resolution BW (RBW) and Video BW (VBW) functions in a Spectrum Analyzer. You may wish to review the "Basics of a Spectrum Analyzer" video if you are unfamiliar with the basic functions and block diagram of a swept spectrum analyzer. Here is the link for that video:
http://www.youtube.com/watch?v=4Y6ji0QBsww
This video covers the definition of these terms, where they exist in the analyzer, what they do, and the effects they have on the displayed results.