According to the form of education, it can be divided into pre-institutional, institutional and non-institutional institutionalized education, which is also called formal education. The core of formal education is the modern school education system. The exact words in the textbook. The problem I do is also the emergence of schools. Online is also ambiguous.

But according to the formal degree of education, it can be divided into institutionalized education and non-institutionalized education. This institutionalization includes pre-system and system, marked by the emergence of schools.

So personally, I think this question is not rigorous.