Investment banking:
https://www.investopedia.com/terms/i/investment-banking.asp
If you want to make it as an investment banker, a mastery of Microsoft Excel is key.
Hedge fund
https://www.investopedia.com/articles/investing/102113/what-are-hedge-funds.asp
Private equity
https://www.investopedia.com/articles/financial-careers/09/private-equity.asp