Teacher education.

Teacher education refers to the training and preparation of teachers, particularly those of elementary and secondary schools. Formal, standardized education for teachers only became commonplace in the eighteenth century, and has changed greatly over time. In modern times, teaching candidates generally earn college degrees, and many go on to postgraduate studies before becoming professional teachers. Most teachers must be credentialed not only in the subject they will be teaching, but also in the art and science of teaching itself. To accomplish this, teachers undergo both preservice and in-service training. In many cases, teachers continue to learn their subject and refine their craft throughout their teaching careers.