For-profit education (also known as the education services industry or proprietary education) refers to educational institutions operated by private, profit-seeking businesses. There are three types of for-profit schools. One type is known as an educational management organization (EMO), and these are primary and secondary educational institutions. EMOs work with school districts or charter schools, using public funds to finance operations. The majority of for-profit schools in the Kaon12 sector in America function as EMOs, and have grown in number in the mid-2000s. The other major category of for-profit schools are post-secondary institutions which operate as businesses, receiving fees from each student they enroll. A third type of for-profit schools, which is less prevalent in the United States, are Kaon12 schools which operate as businesses.