Now that you generally understand risk, you're probably wondering what that looks like in practice.
The assets we’ve talked about so far—stocks and bonds—are quite different in their risk. Bonds are often referred to as fixed income because you are almost always guaranteed the payout you expect. It’s possible that the borrower may default and fail to pay you back, but that is unlikely with reputable bond issuers (like the federal government). There are other risks associated with bonds, but generally, purchasing a bond will return what you expect.
Stocks are much more variable (or volatile) because they depend on the performance of the company. Thus, they are much riskier than bonds. When you buy a stock, it is hard to estimate what return you will receive over time (if any). Nonetheless, the greater the risk, the greater the return.
Diversification
Risk can be reduced by diversifying your portfolio. Diversification is the act of purchasing different types of assets, some riskier than others. This means that even when one aspect of your portfolio is performing poorly, the rest of it could be performing well, resulting in a net gain. Mutual funds and ETFs are based on the idea of diversification. Basically, don’t put all your eggs in one basket and you will probably be okay.
