Education in the United States is provided and controlled primarily by three different levels of government: federal, state and local. Public schools are usually run by school districts, these administered by school boards. The age when school attendance is compulsory varies from state to state. Children and teens are required to attend school until the age of 16 years (or until the completion of high school), in most states. Students may attend public, private or home schools. In the first two, education is divided into three levels: elementary (elementary school), medium (middle school) and secondary (high school).