In the United Kingdom, independent schools (also sometimes described as private schools) are fee-charging schools, typically governed by an elected board of governors and independent of many of the regulations and conditions that apply to state-funded schools. For example, pupils do not have to follow the National Curriculum. Historically, the term 'private school' referred to a school in private ownership, in contrast to an endowed school subject to a trust or of charitable status. Many of the older and more exclusive independent schools catering for the 13–18 age range in England and Wales are known as public schools, seven of which were the subject of the Public Schools Act 1868. The term 'public school' derived from the fact that they were then open to pupils regardless of where they lived or their religion (while in America, 'public school' refers to a publicly funded state school). Prep (preparatory) schools educate younger children up to the age of 13 to 'prepare' them for entry to the public schools and other independent schools. Some former grammar schools converted to an independent fee-charging model following the 1965 Circular 10/65, which marked the end of their state funding; others converted into comprehensive schools.