Stocks represent fractional ownership in a corporation, with each share entitling the holder to a proportional claim on the company's earnings, assets, and voting power—though certain classes may carry different rights, such as preferred stock offering priority dividends without voting rights. These securities are traded either privately (within the private equity realm) or on public stock exchanges, where transactions are heavily regulated to protect investors and prevent fraud. Companies can issue new shares to raise capital, which dilutes existing owners' stakes, or buy back stock to return value, often leading to capital gains for investors. Notably, employee stock options do not grant immediate ownership but rather the right to purchase shares later at a fixed price, potentially yielding a windfall if the market price rises. While shares typically have a nominal par value for accounting in some jurisdictions, the true worth is determined by market dynamics, and the stock certificate historically serves as the legal proof of ownership. Ultimately, stocks are the foundational mechanism through which individuals and institutions share in corporate growth and risk, making them a cornerstone of modern capitalism.