This is the 4404th most frequent Korean word.
학생들을
"Students" (plural, object form).
학생들을 is the object of the verb, indicating who is being waited for.
학생들을 기다리고 있습니다.
I am waiting for the students.
학생들을 is the object receiving the action of teaching.
선생님은 학생들을 많이 가르칩니다.
The teacher teaches many students.
학생들을 is the target beneficiary of the action, specifying whom the help is intended for.