Underwriting is the process in which an investor or investment firm agrees to purchase newly issued securities, such as stocks or bonds, during their initial public offering (IPO) or other forms of issuance. Underwriting involves a commitment to provide capital to the issuer in exchange for securities. In the case of a public securities offering, underwriting is often carried out by investment banks or financial intermediaries, who then offer the securities to the public or institutional investors. The underwriting process allows the issuer to raise the necessary capital for their business or investment plans.