There are three main asset classes which are: stocks (equities), bonds (fixed-income), and cash equivalents (savings accounts, money market funds). However, there are several types of asset classes people can invest in: stocks, crypto, or bonds, to more practical things like art, collectibles, or real estate.
Investing options can also include other financial derivatives that could be added to the asset class mix, which is a wide one, with some investments riskier than others.