What are the "GDR" vs "QFE" hotfixes for SQL Server 2008 R2 SP3? I'd always assumed that higher patch numbers were necessarily later releases, but now I'm not so sure.

Looking at the SQL Server Build List for SQL Server 2008 R2 SP3, there are two possible ways to apply security update MS15-058, one labeled "GDR", and one labeled "QFE".

What's the difference between these?

According to this blog entry, the GDR (general distribution release) are the ones we should all be installing, and the QFEs are the "only if you have this specific issue" releases, or something like that?

If I don't need TLS1.2 support, should I apply the 10.50.6220 patch? Or the 10.50.6529 patch?
To understand the jargons, Aaron Bertrand has a #BackToBasics blog post



Also, refer to this decision matrix for TLS 1.2 support or MS KB - TLS 1.2 support for Microsoft SQL Server

10.50.6220 => SQL Server 2008R2 SP3 GDR 

10.50.6529 =>  SQL Server 2008R2 SP3 QFE

From the decision matirx, if you dont want TLS 1.2 support, dont install 10.50.6542. TLS 1.2 support got introduced in 10.50.6537. 

So to answer your question which one to install ... it will be 10.50.6220.

As always, test out your application behavior when installing a new fix.