A stock, also known as a share or equity, represents a unit of ownership in a company. When you purchase a stock, you become a partial owner of the company and are entitled to a portion of its profits, through dividends or by selling the stock at a higher price. Companies issue stocks as a way to raise capital and fund their operations, growth, and expansion.

Stocks are bought and sold on stock exchanges, such as the New York Stock Exchange (NYSE) or NASDAQ, and their prices can fluctuate based on a variety of factors, such as the performance of the company, overall market conditions, and investor sentiment. Investing in stocks can be a way to grow wealth over the long term, but it also involves risk, as the stock price can decrease as well as increase.