What constitutes what "class" you are in?

Question

On this site I've been reading a lot about people that are lower middle class and upper middle class. I'm not new to living life and working for a living but I have never heard of someone categeorizing themselves within a financial class.

Can someone please clarify why people do this and what constitues what class you are in?

Answer 1

I believe it's socio-economic, meaning it's both your personal prestige and your money.

Lower middle would be barely making it into the average group, while upper would be pretty successful.