This is the 2166th most frequent Korean word.
자세한
Detailed.
Here, '자세한' is used as an adjective to describe '설명' (explanation), emphasizing its thorough and detailed nature.
자세한 설명이 필요할 것 같습니다.
It seems that a detailed explanation is needed.
'자세한' modifies '내용' (content), specifying that the information provided in the document is comprehensive and detailed.
자세한 내용은 첨부된 문서를 참조하세요.
For detailed information, please refer to the attached document.
The word '자세한' is used to qualify '조언' (advice), indicating the advice was thorough and in detail.