Education is the transmission of knowledge, skills, and character traits and comes in many forms. Formal education happens in a complex institutional framework, like public schools. Non-formal education is also structured but takes place outside the formal schooling system, while informal education is unstructured learning through daily experiences. Formal and non-formal education are divided into levels that include early childhood education, primary education, secondary education, and tertiary education. Other classifications focus on the teaching method, like teacher-centered and student-centered education, and on the subject, like science education, language education, and physical education. The term "education" can also refer to the mental states and qualities of educated people and the academic field studying educational phenomena. The precise definition of education is disputed, and there are disagreements about what the aims of education are and to what extent education is different from indoctrination by fostering critical thinking. These disagreements affect how to identify, measure, and improve forms of education. Fundamentally, education socializes children into society by teaching cultural values and norms. It equips them with the skills needed to become productive members of society. This way, it stimulates economic growth and raises awareness of local and global problems. Organized institutions affect many aspects of education. For example, governments set education policies to determine when school classes happen, what is taught, and who can or must attend. International organizations, like UNESCO, have been influential in promoting primary education for all children. Many factors influence whether education is successful. Psychological factors include motivation, intelligence, and personality. Social factors, like socioeconomic status, ethnicity, and gender, are often linked to discrimination. Further factors include access to educational technology, teacher quality, and parent involvement. The main academic field investigating education is called education studies. It examines what education is, what aims and effects it has, and how to improve it. Education studies has many subfields, like philosophy, psychology, sociology, and economics of education. It also discusses comparative education, pedagogy, and the history of education. In prehistory, education happened informally through oral communication and imitation. With the rise of ancient civilizations, writing was invented, and the amount of knowledge grew. This caused a shift from informal to formal education. Initially, formal education was mainly available to elites and religious groups. The invention of the printing press in the 15th century made books more widely available. This increased general literacy. Beginning in the 18th and 19th centuries, public education became more important. This development led to the worldwide process of making primary education available to all, free of charge, and compulsory up to a certain age. Today, over 90% of all primary-school-age children worldwide attend primary school. Source: Wikipedia (en)