What is the different between GDR security update and CU security update What is the different between GDR security update and CU security update? 

I am looking to understand difference between the below two updates. If I apply KB3194724, would it also include KB 3194721?


Build 11.00.6567 (3194724 MS16-136: Description of the security update for SQL Server 2012 Service Pack 3 CU: November 8, 2016)


AND 


Build 11.0.6248.0 (3194721 MS16-136: Description of the security update for SQL Server 2012 Service Pack 3 GDR: November 8, 2016) for SQL Server 2012? 


Which one should I apply if SQL Server 2012 is on SP3?
You should install the latest CU for SQL 2012 SP3. 

As of today (10 May 2017) it is CU8

The SQL version number will give you a good indication of what is more recent.

An explanation of what GDR means can be found here.