What are common stocks?
Simply put, each share of common stock represents a share of ownership in a company. If a company does well or the value of its assets increases, common stock can appreciate in value.
On the other hand, if a company is doing poorly, common stock can decrease in value.
Shares of common stock allow investors to share in a company's success over time, which is why they can make excellent long-term investments.
In general, common stock entitles the holder to vote for corporate directors and to vote on policy changes and stock splits. There are a few exceptions to this rule, but in most cases, you'll have voting rights.
Some companies distribute some of their profits to common stockholders as dividends, and each common stockholder is entitled to a proportional share. But this isn't a requirement.
Common stock vs. preferred stock
The other primary type of stock is called preferred stock and works a bit differently. The main difference is that preferred stock has a fixed, guaranteed dividend, while ordinary stock dividends can change over time or even be discontinued.
For this reason, the share prices of preferred stocks generally don't fluctuate as much as common stock.