The document identifies four main types of businesses: wholesaling, retailing, services, and manufacturing. It examines trends over recent decades that have seen a shift from manufacturing in the 1950s to services and trade businesses dominating by 1970 and through the 2000s. The US Department of Labor predicts the industries expected to see the largest employment growth through 2020 will be in various service sectors, demonstrating the continued expected dominance of service businesses in the US economy.