Also known as nursery education, early childhood education is the process of teaching younger children, usually through play and exploration, that prepares them for more formal school education at a later stage. It is a branch of educational theory that has been built on since the so-called Age of Enlightenment when European educators were looking at ways to improve literacy rates among the population. In modern times, early childhood education has tended to be standardised in the western world. Many of the professionals working in it require a higher level of education and registration under an official inspectorate that aims to maintain standards.