Elementary education consists of the first years of formal, structured education that occur during childhood. In most countries, it is compulsory for children to receive primary education (though in many jurisdictions it is permissible for parents to provide it). Primary education generally begins when children are four to eight years of age.Higher education, also called tertiary, third stage or post secondary education, often known as academia, is the non-compulsory educational level following the completion of a school providing a secondary education, such as a high school, secondary school, or gymnasium. In most contemporary educational systems of the world, secondary education consists of the second years of formal education that occur during adolescence. Education as a science cannot be separated from the educational traditions that existed before. Education was the natural response of early civilizations to the struggle of surviving and thriving as a culture.