How do some people make so much money?

This sounds like a simple question, but I’d just like to have some things clarified. I’m not used to having a lot of money, I know how much I get paid a month, so it’s hard to understand how someone could make literally 10 times as much in the same month.

People that can afford $10,000 a month on a nice apartment in NYC, where are they working? The people that have degrees in very marketable areas like computer science, do they just get hired by some company and receive a huge check every two weeks? Are these jobs that anyone could get with the right degree and experience?

How do raises work for someone that has worked for the same company for 20 years? Is there one huge raise that allows them to go from $50,000 a year to $80,000 a year? Or is it a bunch of small raises over time?