Investment banks are financial institutions that help companies, governments, and other organizations raise capital by underwriting and issuing securities. They play a crucial role in the financial markets by facilitating mergers and acquisitions, providing advisory services, and assisting in the sale of stocks and bonds. These banks also engage in trading and market-making activities, helping to ensure liquidity in the markets. Investment banks typically serve large clients and may have specialized divisions focusing on areas like equity research, fixed income, or asset management. Their expertise helps clients navigate complex financial transactions and strategies.