Bonds are less volatile than stocks, and certainly belong in a well-diversified portfolio. Because they are less volatile than stocks, they're used to make a portfolio more conservative. The same rules that apply to stocks apply to bonds: there are inherent risks, you want to diversify to spread those risks, and you want to invest in bonds passively. Luckily, there are ETFs for bonds as well, that let you instantly diversify, and invest passively.
