Higher education is any of various types of education given in postsecondary institutions of learning and usually affording, at the end of a course of study, a named degree, diploma, or certificate of higher studies. Higher-educational institutions include not only universities and colleges but also various professional schools that provide preparation in such fields as law, theology, medicine, business, music, and art. Higher education also includes teacher-training schools, junior colleges, and institutes of technology. The basic entrance requirement for most higher-educational institutions is the completion of secondary education, and the usual entrance age is about 18 years. The system of higher education had its origin in Europe in the Middle Ages, when the first universities were established. In modern times the nature of higher education around the world has been largely determined by the models established in influential countries such as France, Germany, Great Britain, and the United States.