Investment banks perform two basic, critical functions. First, investment banks act as intermediaries between those entities that demand capital (e.g. corporations) and those that supply it (e.g. investors). This is mainly facilitated through debt and equity offerings by companies. Second, investment banks advise corporations on mergers, acquisitions, restructurings, and other major corporate actions. While the majority of investment banks perform these two functions, it is important to know which products and services each bank pioneer to be in.