Short answers, pulled from the story.
Education is the transmission of knowledge and skills and the development of character traits. Its precise definition is disputed, with theorists disagreeing about its aims and about how it differs from indoctrination.
The three types are formal, non-formal, and informal education. Formal education happens in a complex institutional framework like public schools, non-formal education is structured but outside formal schooling such as tutoring and scouting, and informal education is unstructured learning through daily experiences.
The levels run from early childhood education at level 0, primary education at level 1, secondary education at levels 2 to 3, post-secondary non-tertiary education at level 4, and tertiary education at levels 5 to 8. UNESCO maintains this framework, sorting levels by the student's age, duration of learning, and complexity of content.
Writing, invented starting in the 4th millennium BCE in regions such as Mesopotamia, ancient Egypt, the Indus Valley, and ancient China, allowed information to be stored, preserved, and communicated. This enabled educational tools like textbooks and institutions like schools, and it shifted learning from informal to formal education.
Educational success is influenced by psychological factors like motivation, intelligence, and personality, and by sociological factors like socioeconomic status, ethnicity, and gender. A meta-analysis by Engin Karadağ and colleagues concludes that factors related to the school and the teacher have the biggest impact.
Today, over 90% of all primary-school-age children worldwide attend primary school. In 1970-28% of primary-school-age children did not attend school, and by 2015 that figure had dropped to 9%.
Alternative education is an umbrella term for schooling that differs from the mainstream traditional approach, marked by voluntary participation, small class sizes, and personalized instruction. It includes homeschooling, unschooling, charter schools, and traditions like Montessori schools, Waldorf schools, gurukul schools in India, madrasa schools in the Middle East, and yeshivas.