Corporatism is not fascism. Fasicism is a type of corporatism, but the word is not used in that sense when nowadays such as when people refer to the corporatist wing of the Democratic party versus the progressive wing. Classically, Corporatism refers to a broad family of ideologies which includes fascism, but not all corporatist ideologies are fascist. The "corporation" in "corporatism" doesn't map one-to-one with the common usage of "corporation' on these boards which refers to business corporations. Instead, it's a more general sense of corporations as in "organizations of people" which maps better onto the word "interest groups" as used in the modern political parlance. So, a corporation in the sense of corporatism might include a group of business corporations, e.g. pharmaceutical interest groups, but it can also mean a group of clergymen, or an ethnic group, or labor unions. The defining feature of corporatism is that society is defined by these interest groups. The word corporatism in the modern, pejorative sense is used to mean a capitalist system where business corporations as interest groups, i.e. military-industrial complex, big pharma, big agriculture, etc. control the government. That is, the state is beholden to these groups. Fascism had a corporatist perspective in the classical sense, but in fascism business corporations are entirely beholden to the state to achieve the end-goal of autarky. In fascism, everything is beholden to state nationalist interests. So, it's really a sleight of hand when people equivocate between the two senses of the word. A modern corporatist would negotiate open trade agreements for the interest of the capitalistic class at the expense of the working class, but such a thing would be anathema to the fascist.