This is the 2369th most frequent Spanish word.
vital
Essential; crucial; necessary for life.
Here, 'vital' means essential or very important in the context of achieving or preparing for something.
Es vital que estudies para el examen.
It is vital that you study for the exam.
In this usage, 'vital' refers to a basic and fundamental characteristic necessary for sustaining life.
La función vital de los pulmones es respirar.
The vital function of the lungs is to breathe.
Here, 'vital' conveys the idea of being crucial or significant for the proper functioning or welfare of a group.