작성한

In a sentence

• 나는 보고서를 작성한 후에 제출했다.

  I completed the report and then submitted it.

  Here, '작성한' (completed) is used to modify the noun '보고서를' (report), indicating the action of having completed it.

• 당신이 작성한 이메일은 정말 감동적이었어요.

  The email you wrote was really touching.

  In this sentence, '작성한' is used as a modifier for '이메일' (email), indicating that you are the one who wrote it.

• 사용자가 작성한 데이터는 서버에 저장됩니다.

  The data entered by the user is saved on the server.

  '작성한' modifies '데이터' (data) to show that the user was the one who provided or created the data.