Stocks represent ownership in a company and their value is determined by investor demand. There are different types of stocks including growth stocks, value stocks, large cap stocks and small cap stocks. A stock's price and potential returns are influenced by factors like the company's earnings, dividends, P/E ratio, performance, and intrinsic value. While stock prices fluctuate daily, they tend to increase over the long run as company earnings grow. Investing in stocks provides an opportunity to share in the profits of successful companies.