There are two parties involved in the transaction. One is an issuing company who wants to sell its securities and the other is public who is interested in investment (buying these securities). Investment Banking plays a role of a mediate between the two. What is does is that it advises buyers and sellers on business transactions, its evaluation, pricing and structuring of negotiations. It also helps in the process and implementation. In this way, Investment banking aids companies to build capital fund for themselves and in sale of securities as a mode of investment for individuals.