what is the difference between"about"and "on" when they are used for the meaning of "关于"当about和on都解释成"关于"的时候,它们的用法有什么区别吗?请举例说明一下!

在题目是一般用ON

关于about和on作"关于"讲,
about用于科普类,及专家说给普通人看的东西,
on用于专科类,如专著、专论，专家说给内行人看的。
a book about maths关于数学方面的书，通读本。
a book on amths数学方面的专著。

about是大的方面。
on是具体学科。

on比about更加正式，

ON is used to suggest that a book, article, lecture etc is serious or academic, suitable for specialists.
ABOUT is usual when the information given is more general, or the style of communication is more casual.
A book ABOUT Asia is a book for the general public, whereas a book ON Asia is one for scholars.
Compare:
a book ON African history
a book for children ABOUT Africa and its people
a lecture on economics
a conversation about money
an article on British indutrial problems
an argument about strikes

用about 的时候，一般后面的内容不是太正式，而用on 的时候，关于的内容比较正式，比about 更严谨,一般我们自己都用about,专家，学者所谈论的一般都用on