a) the WORD Ashkenaz in Hebrew MEANS "German", "Norse" or "Northman". That's what it means. That's all it means.
b) Ashkenaz in general have approximately a 95% Y-DNA (Patrilineal) heritage correlation with the Sephardim.
That means they are generally NOT Khazar lineage.
I'm sorry, but the DNA data speaks for itself. There is an interesting recent study that shows some Ashkenaz have some Khazar heritage. That's it. Some have some. But the vast majority's DNA is tightly correlated with Sephardim DNA demonstrating they are genetically one and the same.
Vote me down all you want. Downvotes cannot change scientific data.