Final answer:
A firm commitment underwriting ensures the issuing corporation receives the full amount of the offering, with underwriters keeping any unsold shares. It contrasts with best efforts and all-or-none underwritings, providing certainty of funds to the issuer.
Step-by-step explanation:
The type of offering in which the issuing corporation is ensured of receiving the full amount of the offering and the underwriters retain any unsold shares is known as a firm commitment underwriting. This kind of underwriting arrangement is most beneficial for the company issuing the stock, as it provides certainty of funds regardless of the demand for the shares at the time of the offering.
Underwriters purchase the securities from the issuer and then sell them to the public; if they cannot sell all the shares, they absorb the cost themselves. This is distinct from other forms of offerings such as best efforts underwriting, where the underwriters only sell securities on behalf of the company and have no obligation to purchase unsold shares, or an all-or-none underwriting, which stipulates that the offering must be fully subscribed before any securities can be sold to the public.