What exactly are 'Viking Genetics'

[Hjoi]

I've heard this phrase thrown around many times before but what exactly comprises Viking genetics? What gene or combination of genes produces a typical Scandinavian face with high cheekbones, long foreheads etc? I know it's probably thousands but what exactly does Viking Y chromosome mean and the letters and numbers people use to describe racial stereotypes on this forum? Can you explain these codes to me please because I'm intrigued. Also if you could mix a fundamental Viking DNA (again, what is this?) with the DNA of another racial group, which would it be and why?

[Unome]

Mostly I1 and N1C1 Northern European males.