Koch refers to the Koch brothers, Charles Koch and David Koch, who were influential American businessmen and philanthropists. They co-owned Koch Industries, one of the largest privately held companies in the United States, which operates in various sectors, including oil, chemicals, and consumer products. The brothers were known for their significant political contributions and advocacy for free-market policies. In addition to their business ventures, the Koch brothers were involved in various charitable activities through the Koch Foundation. They supported education, arts, and medical research initiatives. Their influence in politics and philanthropy has sparked both admiration and controversy, making them prominent figures in American society.