Global Data Space s' features

Hello, 
I'm tasked to do a research concerning the Global Data Space s' features of OpenSplice(tested in Java) and OpenDDS..I already downloaded OpenSplice5.4.1 and OpenDDS2.2 and watched the OpenSplice s'videos on Youtube and SlideShare...really i'm lost in an information's flow !! 
Please can you help me !