This is the 2082nd most frequent Korean word.
아이들
"아이들" means "children" in English.
'아이들' here specifically refers to multiple children as the subject of the sentence, performing the action of playing.
아이들은 공원에서 놀고 있어요.
The children are playing in the park.
'아이들' here designates specific children who are the object of the care provided by the parents.
부모님들은 그 아이들을 잘 보살폈습니다.
The parents took good care of the children.
'아이들' is used to describe the intended audience or beneficiary of the book being written, denoting children in general.