A stockholder is someone who owns a piece of a company by holding shares of its stock. When you buy stock, you're buying a small ownership stake in that business, which makes you a stockholder (also called a shareholder).

Imagine a company as a pie divided into millions of tiny slices. Each slice is called a share, and when you own shares, you own those slices of the company. If the company does well and becomes more valuable, your shares become more valuable too. Many companies also share their profits with stockholders through payments called dividends.

Being a stockholder gives you certain rights. You can vote on important company decisions, like who should serve on the board of directors. Large stockholders who own many shares have more influence than small stockholders who own just a few.

People become stockholders hoping their investment will grow over time. But stock ownership involves risk: if a company struggles or fails, stockholders can lose their investment. That's why people often own stock in many different companies rather than putting all their money into just one.