What does it mean when somebody says something like flat 5th? What is a flat and what is a 5th?

Thank you.
5th is a scale degree

c d e f g a b
1 2 3 4 5 6 7

In this case a g. A flat is 1 semitone lower in pitch -> Gb
Quote by razorback91
Im sorry, I just don't see how you could argue that hardcore isn't metal. That just seems arrogant to me.

Yes, its its own kind of metal, but its still metal.
All of this is covered in the theory sticky and the Crusades articles.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.