Juhi, hi
the following may be of interest.
http://www.lkl.ac.uk/ltu/files/publications/comparison Bb9-MDl2 Aug 2010.pdf Dr Kit Logan & Tim Neuman IoE UK: Comparison of Blackboard 9.1 and Moodle 2.0 (may need to Google it if I have got the link wrong), mind you information could be a bit dated now, of course.
Another Google find is 'Differences between Moodle and Blackboard CE' tis a pdf, too big to drag and drop here.
hh
Warm wishes
Dawn