blender 2.78-RC1 is out what is the major difference between these two linux versions? they have two versions one is glibc211 and the other is glibc219

blender-2.78-rc1-linux-glibc211-x86_64.tar.bz2  2016-Sep-02 16:13:25     

blender-2.78-rc1-linux-glibc219-x86_64.tar.bz2  2016-Sep-02 16:15:45    

what is the big difference between the two ~ major benifits between them?
The difference is the version of the GNU "libc" it is linked against. There is no benefit to one or the other -- different versions of Linux use different versions of "libc". Just pick the one with the latest "libc", in this case blender-2.78-rc1-linux-glibc219-x86_64.tar.bz2. It'll most likely work. If it doesn't, try the other one.

Really, there is no difference between the two, except one will work on your system, and the other might not.