This is the 1430th most frequent Korean word.
일제히
Simultaneously; all at once.
Iljehi is used here to indicate that all the students acted at the same time, showing a coordinated action.
학생들이 수업 시작 종소리에 일제히 일어났다.
The students stood up simultaneously at the sound of the class start bell.
Iljehi emphasizes the united timing of the birds flying, indicating simultaneity.
새들이 일제히 하늘로 날아올랐다.
The birds simultaneously took flight into the sky.
Iljehi in this sentence highlights the synchronized reaction of the audience to the event, showcasing a shared moment.