Investment bank is an institution that acts as an underwriter for corporations, but which does not accept deposits or make loans. An investment banks main purpose is to assist companies in raising money through selling securities to the public market. They can help both public and private companies raise capital through debt or equity financing. Debt financing is when a company raises money by borrowing money from the public through the selling of debentures. Equity financing is when a company gives up ownership in the company through the selling of stock to the public. An investment banker can make the process of raising capital much easier for the company. They can also provide advisory services for different types of transactions including mergers and aquisitions. When a client chooses to use an investment bank, the bank is then responsible for preparing all the necessary matierials for the transaction and the completion of the deal.