Could you please explain differences between children's and childrens' and same word's forms?

Question

Answer

"Children's"  means belonging or relating to children. For example 'children's clothes' or 'children's literature.'

The form "childrens' " does not exist. The word 'children' is already plural, so you cannot add an 's' to it.

Answer

childrens не существует

Answer

Children is plural by itself !
But please see the following examples:

1- the student's library (it means the library of a student)
2- the students' library (it means the libraries of a student)

I hope I could tell you the differnce between the " ....'s " and the " .....s' "

Sincerely yours
MehD ftim IRAN