It's a school where the government doesn't fund anything in the school but the parents of the children have to pay for the education and up keep of the school , teachers salaries etc.
Private schools, also known as independent schools or nonstate schools,[1] are not administered by local, state or national governments; thus, they retain the right to select their students and are funded in whole or in part by charging their students tuition, rather than relying on mandatory taxation through public (government) funding; at some private schools students may be able to get a scholarship, which makes the cost cheaper, depending on a talent the student may have e.g. sport scholarship, art scholarship, academic scholarship etc.