This is the 5103rd most frequent Turkish word.
hazırlayan
"Preparer" or "the one who prepares."
Here, 'hazırlayan' specifies the subject, denoting the individual responsible for the action of preparing.
Projeyi hazırlayan öğrenci ödül kazandı.
The student who prepared the project won an award.
Here, 'hazırlayan' functions as a noun modifying the subject, indicating the person who prepared something.
Bu kitabı hazırlayan kişi çok çalışkan.
The person who prepared this book is very diligent.
In this case, 'hazırlayan' is used as part of a defining clause, describing the professional person.