The noun 'children' is the plural form for the noun child, a common, concrete noun; a word for a person or people.
Childrens books
childrens books
What type of noun is childhood
Countryside is a type of common noun.
The noun thunder is a singular, common, concrete noun, a word for a thing.
What type of noun is the word Dell computer What type of noun is the word Dell computer
The children will have type AB
not a noun
Noun
Noun
noun
The form childrens' is not correct.For irregular plural nouns that do not end with an s, add an apostrophe s ('s) to the end of the word (the same as a singular noun that doesn't end with s).We went to the children's playground.